feat(meshcore): report the true connection + add roster/channel management

self_info() reported host/port straight from config regardless of
conn_type, so a serial companion still advertised whatever stale
meshcore_host sat in the config — the API named a device meshai was not
talking to, which is enough to send an investigation to the wrong radio.
Connection details now come from one _connection_descriptor() shared with
connect(), so the log line and the API can't drift; only the live
conn_type's fields are populated and the rest are null.

meshai's device view is otherwise built once at connect and never re-read
— contacts via ensure_contacts(), channels via _enumerate_channels(). The
lib's contact handler only ever merges (meshcore.py::_update_contacts), so
a cached roster can never shrink, and a channel provisioned on the radio
stays invisible until the process restarts. There was no refetch path at
all. Adds an explicit resync that re-reads BOTH halves: a FULL
get_contacts(lastmod=0) reconciled with replace semantics (absent contacts
are dropped) plus a channel re-enumeration, each reporting what changed.

Also adds a preventive route-health check: every region_routes cell whose
MeshCore target cannot be resolved against the live roster/channel table
is surfaced, since such a send fails silently. Room targets are matched by
pubkey prefix, exactly as the dispatcher resolves them, so a picker-stored
prefix is not misreported as dangling. Same-name/different-pubkey roster
entries are flagged too — a name alone cannot identify a contact, which is
the trap behind a room rebuilt under a new keypair.

Backend:
- meshcore_roster.py: pure reconcile_contacts / check_route_health /
  find_name_collisions (no device I/O — unit-testable without a radio)
- transport: _connection_descriptor, resync, refresh_contacts,
  remove_contact, import_contact, export_roster, contacts_synced_at;
  auto_update_contacts enabled (configurable — it costs one incremental
  fetch per advert heard, which is real chatter on a dense mesh)
- API: POST contacts/refresh, DELETE contacts/{pubkey}, GET
  contacts/export, POST contacts/import, GET route-health

Frontend (existing Contacts & Companion page — no new page or nav entry):
- dangling-route + name-collision banners; resync/export/add-contact
  toolbar with last-synced and the added/removed counts; staleness badges;
  search, filters and sortable columns; per-contact delete behind a
  confirm; Companion tab shows the real transport + target.

A full pubkey is required to delete or add: the lib resolves by prefix,
and a prefix could silently hit the wrong node.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

work/dashboard-frontend/src/lib/api.ts

@@ -699,15 +699,25 @@ export interface MeshcoreContact {
 export interface MeshcoreContacts {
   active: boolean
   contacts: MeshcoreContact[]
+  last_synced_at?: number | null  // epoch seconds the roster was pulled from the companion
 }
 export interface MeshcoreSelf {
   name?: string | null
   pubkey?: string | null
   connected: boolean
-  host?: string
-  port?: number
+  // Connection reporting: only the fields for the live `conn_type` are set;
+  // the rest are null. A serial companion has no host/port — showing a config
+  // leftover there would name a device meshai is not actually talking to.
+  conn_type?: 'tcp' | 'serial' | 'ble' | string
+  target?: string           // human-readable: "serial:/dev/x@115200" | "host:port" | "ble:addr"
+  host?: string | null
+  port?: number | null
+  serial_port?: string | null
+  baud?: number | null
+  ble_address?: string | null
   channel_count?: number
   last_advert_sent?: number | null  // epoch seconds; null/absent = never advertised
+  contacts_synced_at?: number | null
 }
 
 export async function fetchMeshcoreContacts(): Promise<MeshcoreContacts> {
@@ -717,6 +727,109 @@ export async function fetchMeshcoreSelf(): Promise<MeshcoreSelf> {
   return fetchJson<MeshcoreSelf>('/api/meshcore/self')
 }
 
+// Result of a full roster resync: what the reconcile actually changed.
+export interface MeshcoreRefreshStats {
+  before: number
+  after: number
+  added: number
+  removed: number
+  updated: number
+  added_keys: string[]
+  removed_keys: string[]
+}
+// Channels are also a connect-time snapshot, so a resync re-reads them too.
+export interface MeshcoreChannelStats {
+  before: number
+  after: number
+  added: string[]
+  removed: string[]
+}
+export interface MeshcoreRefreshResult {
+  active: boolean
+  stats: MeshcoreRefreshStats
+  channel_stats: MeshcoreChannelStats
+  contacts: MeshcoreContact[]
+  channels: string[]
+  last_synced_at: number | null
+}
+
+// Re-read the companion's device view: FULL contact refetch + reconcile (drops
+// contacts the companion no longer has) AND channel re-enumeration. Throws with
+// the backend's `detail` when MeshCore is not connected or the fetch fails.
+export async function refreshMeshcoreContacts(): Promise<MeshcoreRefreshResult> {
+  const response = await fetch('/api/meshcore/contacts/refresh', { method: 'POST' })
+  if (!response.ok) {
+    const body = await response.json().catch(() => null)
+    throw new Error(body?.detail || `API error: ${response.status} ${response.statusText}`)
+  }
+  return response.json()
+}
+
+// Write contact records onto the companion (upsert; nothing is removed, and no
+// mesh traffic is generated). Used both for a manual single add — e.g. after a
+// room server is rebuilt with a new keypair — and for restoring an exported
+// roster onto a replacement companion.
+export interface MeshcoreImportResult {
+  active: boolean
+  imported: number
+  failed: number
+  errors: { pubkey: string | null; detail: string }[]
+}
+export async function importMeshcoreContacts(
+  contacts: Record<string, unknown>[],
+): Promise<MeshcoreImportResult> {
+  const response = await fetch('/api/meshcore/contacts/import', {
+    method: 'POST',
+    headers: { 'Content-Type': 'application/json' },
+    body: JSON.stringify({ contacts }),
+  })
+  if (!response.ok) {
+    const body = await response.json().catch(() => null)
+    throw new Error(body?.detail || `API error: ${response.status} ${response.statusText}`)
+  }
+  return response.json()
+}
+
+// Remove a contact from the companion. Requires the FULL 64-hex pubkey.
+export async function removeMeshcoreContact(pubkey: string): Promise<MeshcoreContacts> {
+  const response = await fetch(`/api/meshcore/contacts/${encodeURIComponent(pubkey)}`, {
+    method: 'DELETE',
+  })
+  if (!response.ok) {
+    const body = await response.json().catch(() => null)
+    throw new Error(body?.detail || `API error: ${response.status} ${response.statusText}`)
+  }
+  return response.json()
+}
+
+// A routing cell whose MeshCore target does not resolve on the companion.
+export interface MeshcoreDanglingRoute {
+  family: string
+  region: string
+  target: string
+  kind: 'room' | 'channel' | string
+  reason: 'room_not_found' | 'channel_not_found' | 'not_a_room' | string
+  enabled: boolean
+}
+// Roster entries sharing a name but not a keypair — indistinguishable by name.
+export interface MeshcoreNameCollision {
+  name: string
+  count: number
+  contacts: { pubkey: string; type: number | null }[]
+}
+export interface MeshcoreRouteHealth {
+  active: boolean
+  dangling: MeshcoreDanglingRoute[]
+  dangling_enabled: number
+  collisions: MeshcoreNameCollision[]
+  checked: number
+  mc_enabled: boolean
+}
+
+export async function fetchMeshcoreRouteHealth(): Promise<MeshcoreRouteHealth> {
+  return fetchJson<MeshcoreRouteHealth>('/api/meshcore/route-health')
+}
+
 export async function sendMeshcoreAdvert(): Promise<TestSendResult> {
   const response = await fetch('/api/meshcore/advert', {
     method: 'POST',

work/dashboard-frontend/src/pages/MeshCoreCompanion.tsx

@@ -10,6 +10,32 @@ import {
   type TestSendResult,
 } from '../lib/api'
 
+// How meshai is attached to the companion. Distinct colours so the transport is
+// readable at a glance — an operator must be able to tell WHICH device this is
+// before acting on it.
+const CONN_TYPE_BADGE: Record<string, string> = {
+  serial: 'bg-emerald-500/15 text-emerald-400',
+  tcp: 'bg-sky-500/15 text-sky-400',
+  ble: 'bg-violet-500/15 text-violet-400',
+}
+
+/** The live connection target, from whichever fields belong to this conn_type.
+ *
+ * Falls back to the per-transport fields if `target` is absent (older backend).
+ * Never falls back to host/port for a non-TCP link: that is exactly the
+ * mistake this display exists to prevent.
+ */
+function connectionTarget(self: MeshcoreSelf | null): string {
+  if (!self) return '—'
+  if (self.target) return self.target
+  if (self.conn_type === 'serial') {
+    return self.serial_port ? `${self.serial_port}@${self.baud ?? 115200}` : 'serial'
+  }
+  if (self.conn_type === 'ble') return self.ble_address || 'ble'
+  if (self.host) return `${self.host}${self.port != null ? `:${self.port}` : ''}`
+  return '—'
+}
+
 /** Format epoch seconds as a human-readable relative time string. */
 function relativeTime(epochSec: number): string {
   const diffSec = Math.floor(Date.now() / 1000 - epochSec)
@@ -178,10 +204,18 @@ export default function MeshCoreCompanion() {
                     <dd className="text-slate-100">{self?.name ?? 'unnamed'}</dd>
                   </div>
                   <div>
-                    <dt className="text-[#777] mb-1">Host</dt>
-                    <dd className="text-slate-100 font-mono">
-                      {self?.host ?? '—'}
-                      {self?.port != null ? `:${self.port}` : ''}
+                    <dt className="text-[#777] mb-1">Connection</dt>
+                    <dd className="flex items-center gap-2">
+                      <span
+                        className={`px-1.5 py-0.5 text-[10px] uppercase tracking-wide rounded ${
+                          CONN_TYPE_BADGE[self?.conn_type ?? ''] ?? 'bg-slate-600/30 text-slate-400'
+                        }`}
+                      >
+                        {self?.conn_type ?? 'unknown'}
+                      </span>
+                      <span className="text-slate-100 font-mono text-xs break-all">
+                        {connectionTarget(self)}
+                      </span>
                     </dd>
                   </div>
                   <div className="sm:col-span-2">

work/dashboard-frontend/src/pages/MeshCoreContacts.tsx

@@ -1,13 +1,20 @@
-import { Fragment, useCallback, useEffect, useState } from 'react'
-import { Users } from 'lucide-react'
+import { Fragment, useCallback, useEffect, useMemo, useState } from 'react'
+import { AlertTriangle, Copy, Download, Plus, RefreshCw, Trash2, Users } from 'lucide-react'
 import {
   fetchMeshcoreContacts,
+  fetchMeshcoreRouteHealth,
   fetchMeshcoreTelemetry,
   fetchConnectionConfig,
+  importMeshcoreContacts,
   pollMeshcoreContact,
+  refreshMeshcoreContacts,
+  removeMeshcoreContact,
   updateConfig,
+  type MeshcoreChannelStats,
   type MeshcoreContacts,
   type MeshcoreContact,
+  type MeshcoreRefreshStats,
+  type MeshcoreRouteHealth,
   type MeshcoreTelemetry,
   type MeshcoreTelemetryEntry,
   type MeshcoreTelemetryData,
@@ -18,10 +25,32 @@ import {
 const TELEMETRY_POLL_MS = 15000
 const MIN_INTERVAL_MINUTES = 5
 
-// Relative time for epoch-seconds fields (last_advert).
+// A contact not heard from in this long is flagged stale. Adverts are typically
+// hours apart, so days — not hours — is the honest threshold for "gone quiet".
+const STALE_AFTER_DAYS = 14
+const STALE_AFTER_SECONDS = STALE_AFTER_DAYS * 86400
+
+type SortKey = 'name' | 'type' | 'last_advert'
+type TypeFilter = 'all' | 'rooms' | 'stale'
+
+function isStale(c: MeshcoreContact): boolean {
+  if (c.last_advert == null || c.last_advert <= 0) return false
+  return Math.floor(Date.now() / 1000) - c.last_advert > STALE_AFTER_SECONDS
+}
+
+// Why a routing cell will not resolve, in operator language.
+const DANGLING_REASON: Record<string, string> = {
+  room_not_found: 'no room server with this key is on the companion',
+  channel_not_found: 'this channel is not on the companion',
+  not_a_room: 'this key belongs to a contact that is not a room server',
+}
+
+// Relative time for epoch-seconds fields (last_advert, last_synced_at).
+// Floors the DIFFERENCE, not just the clock: last_synced_at is a float, so
+// flooring only Date.now() would leave a fractional "28.6851...s ago".
 function relativeTime(epochSeconds: number | null): string {
   if (epochSeconds == null) return '—'
-  const diff = Math.floor(Date.now() / 1000) - epochSeconds
+  const diff = Math.floor(Date.now() / 1000 - epochSeconds)
   if (diff < 0) return 'just now'
   if (diff < 60) return `${diff}s ago`
   const mins = Math.floor(diff / 60)
@@ -145,6 +174,31 @@ export default function MeshCoreContacts() {
   const [connectionConfig, setConnectionConfig] = useState<ConnectionConfig | null>(null)
   const [telemetry, setTelemetry] = useState<MeshcoreTelemetry | null>(null)
 
+  // Roster management: resync / export / delete / route health.
+  const [routeHealth, setRouteHealth] = useState<MeshcoreRouteHealth | null>(null)
+  const [resyncing, setResyncing] = useState(false)
+  const [resyncStats, setResyncStats] = useState<MeshcoreRefreshStats | null>(null)
+  const [channelStats, setChannelStats] = useState<MeshcoreChannelStats | null>(null)
+  const [lastSyncedAt, setLastSyncedAt] = useState<number | null>(null)
+
+  // Manual add — the companion learns most contacts by advert, but a node that
+  // has been rekeyed (or is not yet heard) has to be entered by key.
+  const [showAdd, setShowAdd] = useState(false)
+  const [addName, setAddName] = useState('')
+  const [addPubkey, setAddPubkey] = useState('')
+  const [addType, setAddType] = useState(1)
+  const [adding, setAdding] = useState(false)
+  const [addError, setAddError] = useState<string | null>(null)
+  const [confirmDelete, setConfirmDelete] = useState<string | null>(null)
+  const [deletingId, setDeletingId] = useState<string | null>(null)
+  const [expandedKey, setExpandedKey] = useState<string | null>(null)
+
+  // Table controls.
+  const [search, setSearch] = useState('')
+  const [typeFilter, setTypeFilter] = useState<TypeFilter>('all')
+  const [sortKey, setSortKey] = useState<SortKey>('name')
+  const [sortAsc, setSortAsc] = useState(true)
+
   // Per-row transient UI state.
   const [savingId, setSavingId] = useState<string | null>(null)
   const [savedId, setSavedId] = useState<string | null>(null)
@@ -169,7 +223,10 @@ export default function MeshCoreContacts() {
       setError(null)
       try {
         const result = await fetchMeshcoreContacts()
-        if (!cancelled) setData(result)
+        if (!cancelled) {
+          setData(result)
+          setLastSyncedAt(result.last_synced_at ?? null)
+        }
       } catch (err) {
         if (!cancelled) {
           setError(err instanceof Error ? err.message : 'Failed to load contacts')
@@ -183,6 +240,21 @@ export default function MeshCoreContacts() {
     }
   }, [])
 
+  // Route health (once): which routing cells point at something that no longer
+  // exists. Non-fatal — the roster is still useful if this check fails.
+  const loadRouteHealth = useCallback(async () => {
+    try {
+      const health = await fetchMeshcoreRouteHealth()
+      setRouteHealth(health)
+    } catch {
+      // non-fatal — banner simply stays hidden
+    }
+  }, [])
+
+  useEffect(() => {
+    loadRouteHealth()
+  }, [loadRouteHealth])
+
   // Connection config (once) — kept whole so PUTs send it back intact.
   useEffect(() => {
     let cancelled = false
@@ -292,6 +364,150 @@ export default function MeshCoreContacts() {
     }
   }, [])
 
+  // Full resync: refetch the whole roster from the node and reconcile, so
+  // entries the companion no longer has are dropped rather than lingering.
+  const handleResync = useCallback(async () => {
+    setResyncing(true)
+    setResyncStats(null)
+    setChannelStats(null)
+    setSaveError(null)
+    try {
+      const result = await refreshMeshcoreContacts()
+      setData({ active: result.active, contacts: result.contacts })
+      setLastSyncedAt(result.last_synced_at)
+      setResyncStats(result.stats)
+      setChannelStats(result.channel_stats)
+      // Roster and channels just changed — re-check the routing cells against them.
+      loadRouteHealth()
+    } catch (err) {
+      setSaveError(err instanceof Error ? err.message : 'Resync failed')
+    } finally {
+      setResyncing(false)
+    }
+  }, [loadRouteHealth])
+
+  // Add a contact by key. Minimal record: the companion fills in the rest when
+  // the node next adverts; out_path_len -1 means "flood until a path is known".
+  const handleAdd = useCallback(async () => {
+    const pubkey = addPubkey.trim().toLowerCase()
+    const name = addName.trim()
+    if (!/^[0-9a-f]{64}$/.test(pubkey)) {
+      setAddError('Pubkey must be exactly 64 hex characters (the full key, not a prefix)')
+      return
+    }
+    if (!name) {
+      setAddError('A name is required')
+      return
+    }
+    setAdding(true)
+    setAddError(null)
+    try {
+      const result = await importMeshcoreContacts([
+        { pubkey, name, type: addType, flags: 0, out_path_len: -1, out_path: '', last_advert: 0 },
+      ])
+      if (result.failed > 0) {
+        setAddError(result.errors[0]?.detail || 'Add failed')
+        return
+      }
+      setShowAdd(false)
+      setAddName('')
+      setAddPubkey('')
+      // Re-read so the new contact appears with whatever the companion stored.
+      const refreshed = await fetchMeshcoreContacts()
+      setData(refreshed)
+      setLastSyncedAt(refreshed.last_synced_at ?? null)
+      loadRouteHealth()
+    } catch (err) {
+      setAddError(err instanceof Error ? err.message : 'Add failed')
+    } finally {
+      setAdding(false)
+    }
+  }, [addPubkey, addName, addType, loadRouteHealth])
+
+  // Export streams from the API (not from component state) so the file is the
+  // full importable record set, not the display projection shown in the table.
+  const handleExport = useCallback(() => {
+    window.location.href = '/api/meshcore/contacts/export'
+  }, [])
+
+  const handleDelete = useCallback(async (c: MeshcoreContact) => {
+    setDeletingId(c.pubkey)
+    setSaveError(null)
+    try {
+      const result = await removeMeshcoreContact(c.pubkey)
+      setData((prev) => ({ active: true, contacts: result.contacts, last_synced_at: prev?.last_synced_at ?? null }))
+      setConfirmDelete(null)
+      loadRouteHealth()
+    } catch (err) {
+      setSaveError(err instanceof Error ? err.message : 'Delete failed')
+    } finally {
+      setDeletingId((d) => (d === c.pubkey ? null : d))
+    }
+  }, [loadRouteHealth])
+
+  const handleCopyPubkey = useCallback(async (pubkey: string) => {
+    try {
+      await navigator.clipboard.writeText(pubkey)
+    } catch {
+      // clipboard unavailable (non-secure context) — no-op
+    }
+  }, [])
+
+  const toggleSort = useCallback((key: SortKey) => {
+    setSortKey((prev) => {
+      if (prev === key) {
+        setSortAsc((asc) => !asc)
+        return prev
+      }
+      setSortAsc(true)
+      return key
+    })
+  }, [])
+
+  // Names collide across keypairs, so a name alone cannot identify a contact.
+  // Flag the ambiguous ones inline rather than leaving two identical rows.
+  const collidingNames = useMemo(() => {
+    const names = new Set<string>()
+    for (const collision of routeHealth?.collisions ?? []) names.add(collision.name)
+    return names
+  }, [routeHealth])
+
+  const visibleContacts = useMemo(() => {
+    let list = data?.contacts ?? []
+    const needle = search.trim().toLowerCase()
+    if (needle) {
+      list = list.filter(
+        (c) =>
+          (c.name ?? '').toLowerCase().includes(needle) ||
+          c.pubkey.toLowerCase().includes(needle)
+      )
+    }
+    if (typeFilter === 'rooms') list = list.filter((c) => c.type === 3)
+    else if (typeFilter === 'stale') list = list.filter(isStale)
+
+    const sorted = [...list].sort((a, b) => {
+      let cmp = 0
+      if (sortKey === 'name') {
+        cmp = (a.name ?? '').localeCompare(b.name ?? '')
+      } else if (sortKey === 'type') {
+        cmp = (a.type ?? 0) - (b.type ?? 0)
+      } else {
+        cmp = (a.last_advert ?? 0) - (b.last_advert ?? 0)
+      }
+      return sortAsc ? cmp : -cmp
+    })
+    return sorted
+  }, [data, search, typeFilter, sortKey, sortAsc])
+
+  const staleCount = useMemo(
+    () => (data?.contacts ?? []).filter(isStale).length,
+    [data]
+  )
+  const roomCount = useMemo(
+    () => (data?.contacts ?? []).filter((c) => c.type === 3).length,
+    [data]
+  )
+
   const handleSaveInterval = useCallback(async () => {
     if (!connectionConfig) return
     const minutes = Math.max(MIN_INTERVAL_MINUTES, Math.round(intervalMinutes) || MIN_INTERVAL_MINUTES)
@@ -316,9 +532,11 @@ export default function MeshCoreContacts() {
   }, [connectionConfig, intervalMinutes])
 
   const rosterActive = data?.active !== false
+  const dangling = routeHealth?.dangling ?? []
+  const collisions = routeHealth?.collisions ?? []
 
   return (
-    <div className="max-w-4xl mx-auto space-y-4">
+    <div className="max-w-5xl mx-auto space-y-4">
       {/* Header */}
       <div className="flex items-center gap-4">
         <div className="flex-shrink-0 w-12 h-12 rounded-lg bg-[#0a0e17] border border-[#1e2a3a] flex items-center justify-center">
@@ -333,6 +551,192 @@ export default function MeshCoreContacts() {
         </div>
       </div>
 
+      {/* Dangling-route warning — a cell pointing into the void fails SILENTLY
+          at send time, so this is the only place it becomes visible. */}
+      {dangling.length > 0 && (
+        <div className="border border-red-500/40 bg-red-500/10 p-4 space-y-2">
+          <div className="flex items-start gap-3">
+            <AlertTriangle size={18} className="text-red-400 flex-shrink-0 mt-0.5" />
+            <div className="space-y-2 min-w-0">
+              <h3 className="text-sm font-semibold text-red-300">
+                {dangling.length} routing {dangling.length === 1 ? 'cell points' : 'cells point'} at a
+                destination that no longer exists
+              </h3>
+              <p className="text-xs text-red-300/70 max-w-prose">
+                These cells cannot be delivered — a send to a missing room or channel fails
+                silently. Fix the target on the Routing page, or resync if the roster is stale.
+              </p>
+              <ul className="space-y-1">
+                {dangling.map((d) => (
+                  <li
+                    key={`${d.family}-${d.region}-${d.target}`}
+                    className="text-xs text-slate-200 flex flex-wrap items-center gap-x-2 gap-y-1"
+                  >
+                    <span className="px-1.5 py-0.5 rounded bg-red-500/20 text-red-300 uppercase tracking-wide text-[10px]">
+                      {d.family}
+                    </span>
+                    <span className="text-slate-300">{d.region}</span>
+                    <span className="text-[#777]">→</span>
+                    <span className="font-mono text-[11px] text-red-300 break-all">{d.target}</span>
+                    <span className="text-[#777]">
+                      — {DANGLING_REASON[d.reason] ?? d.reason}
+                    </span>
+                    {!d.enabled && (
+                      <span className="px-1.5 py-0.5 rounded bg-slate-600/30 text-slate-400 text-[10px] uppercase tracking-wide">
+                        disabled
+                      </span>
+                    )}
+                  </li>
+                ))}
+              </ul>
+            </div>
+          </div>
+        </div>
+      )}
+
+      {/* Name collisions — two keypairs advertising the same name are
+          indistinguishable in any name-based picker. */}
+      {collisions.length > 0 && (
+        <div className="border border-amber-500/40 bg-amber-500/10 p-4">
+          <div className="flex items-start gap-3">
+            <AlertTriangle size={18} className="text-amber-400 flex-shrink-0 mt-0.5" />
+            <div className="space-y-2 min-w-0">
+              <h3 className="text-sm font-semibold text-amber-300">
+                {collisions.length} duplicated {collisions.length === 1 ? 'name' : 'names'} on the roster
+              </h3>
+              <p className="text-xs text-amber-300/70 max-w-prose">
+                These names each map to more than one public key. A name alone cannot identify
+                them — always confirm the key before routing to or deleting one.
+              </p>
+              <ul className="space-y-1">
+                {collisions.map((c) => (
+                  <li key={c.name} className="text-xs text-slate-200">
+                    <span className="text-slate-100">{c.name}</span>{' '}
+                    <span className="text-[#777]">×{c.count}</span>
+                    <span className="ml-2 font-mono text-[11px] text-amber-300/80">
+                      {c.contacts.map((x) => shortPubkey(x.pubkey)).join('  ·  ')}
+                    </span>
+                  </li>
+                ))}
+              </ul>
+            </div>
+          </div>
+        </div>
+      )}
+
+      {/* Roster toolbar: sync state + resync/export */}
+      {rosterActive && (
+        <div className="bg-bg-card border border-border p-4 space-y-3">
+          <div className="flex flex-wrap items-center gap-3">
+            <button
+              onClick={handleResync}
+              disabled={resyncing}
+              className="flex items-center gap-2 px-3 py-1.5 text-sm rounded bg-accent/15 text-accent hover:bg-accent/25 disabled:opacity-50"
+              title="Refetch the full roster from the companion and drop entries it no longer has"
+            >
+              <RefreshCw size={14} className={resyncing ? 'animate-spin' : undefined} />
+              {resyncing ? 'Resyncing…' : 'Resync from node'}
+            </button>
+            <button
+              onClick={handleExport}
+              className="flex items-center gap-2 px-3 py-1.5 text-sm rounded bg-[#0a0e17] border border-[#1e2a3a] text-slate-200 hover:border-accent/40"
+              title="Download the roster as JSON"
+            >
+              <Download size={14} />
+              Export JSON
+            </button>
+            <button
+              onClick={() => { setShowAdd((s) => !s); setAddError(null) }}
+              className="flex items-center gap-2 px-3 py-1.5 text-sm rounded bg-[#0a0e17] border border-[#1e2a3a] text-slate-200 hover:border-accent/40"
+              title="Add a contact by public key"
+            >
+              <Plus size={14} />
+              Add contact
+            </button>
+            <span className="text-xs text-[#777]">
+              Last synced {lastSyncedAt != null ? relativeTime(lastSyncedAt) : 'unknown'}
+            </span>
+            {resyncStats && (
+              <span className="text-xs text-slate-300">
+                <span className="text-emerald-400">+{resyncStats.added} added</span>
+                {' · '}
+                <span className="text-red-400">−{resyncStats.removed} removed</span>
+                {' · '}
+                <span className="text-[#777]">{resyncStats.updated} updated</span>
+                {' · '}
+                <span className="text-[#777]">{resyncStats.after} total</span>
+                {channelStats && (
+                  <span className="text-[#777]">
+                    {' · '}channels {channelStats.after}
+                    {channelStats.added.length > 0 && (
+                      <span className="text-emerald-400"> +{channelStats.added.length}</span>
+                    )}
+                    {channelStats.removed.length > 0 && (
+                      <span className="text-red-400"> −{channelStats.removed.length}</span>
+                    )}
+                  </span>
+                )}
+              </span>
+            )}
+          </div>
+
+          {/* Add a contact by key — the companion learns most nodes by advert,
+              but a rekeyed or out-of-range node has to be entered manually. */}
+          {showAdd && (
+            <div className="border border-[#1e2a3a] bg-[#0a0e17] p-3 space-y-2">
+              <div className="flex flex-wrap items-center gap-2">
+                <input
+                  value={addName}
+                  onChange={(e) => setAddName(e.target.value)}
+                  placeholder="Name"
+                  className="w-40 px-2 py-1 text-sm bg-bg-card border border-[#1e2a3a] rounded text-slate-100 placeholder:text-[#555]"
+                />
+                <input
+                  value={addPubkey}
+                  onChange={(e) => setAddPubkey(e.target.value)}
+                  placeholder="Full 64-character hex public key"
+                  className="flex-1 min-w-[280px] px-2 py-1 text-sm font-mono bg-bg-card border border-[#1e2a3a] rounded text-slate-100 placeholder:text-[#555]"
+                />
+                <select
+                  value={addType}
+                  onChange={(e) => setAddType(Number(e.target.value))}
+                  className="px-2 py-1 text-sm bg-bg-card border border-[#1e2a3a] rounded text-slate-200"
+                >
+                  <option value={1}>Chat</option>
+                  <option value={2}>Repeater</option>
+                  <option value={3}>Room</option>
+                  <option value={4}>Sensor</option>
+                </select>
+                <button
+                  onClick={handleAdd}
+                  disabled={adding}
+                  className="px-3 py-1 text-sm rounded bg-accent/15 text-accent hover:bg-accent/25 disabled:opacity-50"
+                >
+                  {adding ? 'Adding…' : 'Add'}
+                </button>
+                <button
+                  onClick={() => setShowAdd(false)}
+                  className="px-2 py-1 text-sm text-[#777] hover:text-slate-200"
+                >
+                  Cancel
+                </button>
+              </div>
+              {addError && <p className="text-xs text-red-400">{addError}</p>}
+              <p className="text-xs text-[#777] max-w-prose">
+                Writes the contact straight to the companion &mdash; nothing is transmitted. Use this
+                when a node has been rebuilt with a new keypair, or is not yet in range to advert.
+              </p>
+            </div>
+          )}
+
+          <p className="text-xs text-[#777] max-w-prose">
+            The roster and channel list are a snapshot cached from the companion at connect. Resync
+            re-reads both from the node and reconciles them &mdash; the only action that removes
+            entries the companion has dropped, or picks up a channel added on the radio.
+          </p>
+        </div>
+      )}
+
       {/* Auto-poll interval control */}
       {rosterActive && connectionConfig && (
         <div className="bg-bg-card border border-border p-4 space-y-2">
@@ -389,13 +793,56 @@ export default function MeshCoreContacts() {
           </p>
         </div>
       ) : (
-        <div className="bg-bg-card border border-border overflow-x-auto">
+        <div className="bg-bg-card border border-border">
+          {/* Filter / search toolbar */}
+          <div className="flex flex-wrap items-center gap-3 px-4 py-3 border-b border-border">
+            <input
+              type="search"
+              value={search}
+              onChange={(e) => setSearch(e.target.value)}
+              placeholder="Search name or pubkey…"
+              className="flex-1 min-w-[180px] px-2 py-1 text-sm bg-[#0a0e17] border border-[#1e2a3a] rounded text-slate-100 placeholder:text-[#555]"
+            />
+            <div className="flex gap-1">
+              {([
+                { key: 'all', label: `All ${data?.contacts.length ?? 0}` },
+                { key: 'rooms', label: `Rooms ${roomCount}` },
+                { key: 'stale', label: `Stale ${staleCount}` },
+              ] as const).map(({ key, label }) => (
+                <button
+                  key={key}
+                  onClick={() => setTypeFilter(key)}
+                  className={`px-2.5 py-1 text-xs rounded border transition-colors ${
+                    typeFilter === key
+                      ? 'border-accent/40 bg-accent/15 text-accent'
+                      : 'border-[#1e2a3a] bg-[#0a0e17] text-[#777] hover:text-slate-200'
+                  }`}
+                >
+                  {label}
+                </button>
+              ))}
+            </div>
+          </div>
+
+          <div className="overflow-x-auto">
           <table className="w-full text-sm">
             <thead>
               <tr className="border-b border-border text-left text-[11px] uppercase tracking-wide text-[#777]">
-                <th className="px-4 py-2.5 font-medium">Name</th>
-                <th className="px-4 py-2.5 font-medium">Type</th>
-                <th className="px-4 py-2.5 font-medium">Last heard</th>
+                <th className="px-4 py-2.5 font-medium">
+                  <button onClick={() => toggleSort('name')} className="hover:text-slate-200 uppercase">
+                    Name{sortKey === 'name' ? (sortAsc ? ' ▲' : ' ▼') : ''}
+                  </button>
+                </th>
+                <th className="px-4 py-2.5 font-medium">
+                  <button onClick={() => toggleSort('type')} className="hover:text-slate-200 uppercase">
+                    Type{sortKey === 'type' ? (sortAsc ? ' ▲' : ' ▼') : ''}
+                  </button>
+                </th>
+                <th className="px-4 py-2.5 font-medium">
+                  <button onClick={() => toggleSort('last_advert')} className="hover:text-slate-200 uppercase">
+                    Last heard{sortKey === 'last_advert' ? (sortAsc ? ' ▲' : ' ▼') : ''}
+                  </button>
+                </th>
                 <th className="px-4 py-2.5 font-medium">Position</th>
                 <th className="px-4 py-2.5 font-medium">Pubkey</th>
                 <th className="px-4 py-2.5 font-medium">Auto-poll</th>
@@ -403,7 +850,7 @@ export default function MeshCoreContacts() {
               </tr>
             </thead>
             <tbody className="divide-y divide-border">
-              {(data?.contacts ?? []).map((c) => {
+              {visibleContacts.map((c) => {
                 const id = contactId(c)
                 const entry = entryFor(c)
                 const selected = isSelected(c)
@@ -437,14 +884,53 @@ export default function MeshCoreContacts() {
                 return (
                   <Fragment key={c.pubkey}>
                     <tr className="hover:bg-bg-hover">
-                      <td className="px-4 py-2.5 text-slate-100">{contactName(c)}</td>
+                      <td className="px-4 py-2.5 text-slate-100">
+                        <div className="flex items-center gap-2">
+                          <span>{contactName(c)}</span>
+                          {c.name != null && collidingNames.has(c.name) && (
+                            <span
+                              className="px-1.5 py-0.5 text-[10px] uppercase tracking-wide rounded bg-amber-500/15 text-amber-400"
+                              title="Another contact advertises this same name with a different key — check the pubkey"
+                            >
+                              dup name
+                            </span>
+                          )}
+                        </div>
+                      </td>
                       <td className="px-4 py-2.5">
                         <TypeBadge type={c.type} />
                       </td>
-                      <td className="px-4 py-2.5 text-slate-300">{relativeTime(c.last_advert)}</td>
+                      <td className="px-4 py-2.5">
+                        <div className="flex items-center gap-2">
+                          <span className="text-slate-300">{relativeTime(c.last_advert)}</span>
+                          {isStale(c) && (
+                            <span
+                              className="px-1.5 py-0.5 text-[10px] uppercase tracking-wide rounded bg-orange-500/15 text-orange-400"
+                              title={`Not heard from in over ${STALE_AFTER_DAYS} days`}
+                            >
+                              stale
+                            </span>
+                          )}
+                        </div>
+                      </td>
                       <td className="px-4 py-2.5 text-slate-300 font-mono text-xs">{position(c)}</td>
                       <td className="px-4 py-2.5 text-slate-400 font-mono text-xs">
-                        {shortPubkey(c.pubkey)}
+                        <div className="flex items-center gap-1.5">
+                          <button
+                            onClick={() => setExpandedKey((k) => (k === c.pubkey ? null : c.pubkey))}
+                            className="hover:text-accent"
+                            title={c.pubkey}
+                          >
+                            {expandedKey === c.pubkey ? c.pubkey : shortPubkey(c.pubkey)}
+                          </button>
+                          <button
+                            onClick={() => handleCopyPubkey(c.pubkey)}
+                            className="text-[#555] hover:text-accent flex-shrink-0"
+                            title="Copy full pubkey"
+                          >
+                            <Copy size={11} />
+                          </button>
+                        </div>
                       </td>
                       <td className="px-4 py-2.5">
                         <label
@@ -472,15 +958,55 @@ export default function MeshCoreContacts() {
                         </label>
                       </td>
                       <td className="px-4 py-2.5">
-                        <button
-                          onClick={() => handlePollNow(c)}
-                          disabled={pollingId === id}
-                          className="px-2 py-1 text-xs rounded bg-accent/15 text-accent hover:bg-accent/25 disabled:opacity-50"
-                        >
-                          {pollingId === id ? 'Polling…' : 'Poll now'}
-                        </button>
+                        <div className="flex items-center justify-end gap-1.5">
+                          <button
+                            onClick={() => handlePollNow(c)}
+                            disabled={pollingId === id}
+                            className="px-2 py-1 text-xs rounded bg-accent/15 text-accent hover:bg-accent/25 disabled:opacity-50"
+                          >
+                            {pollingId === id ? 'Polling…' : 'Poll now'}
+                          </button>
+                          {/* Two-step delete: removal from the companion is
+                              permanent — the node must be rediscovered. */}
+                          {confirmDelete === c.pubkey ? (
+                            <>
+                              <button
+                                onClick={() => handleDelete(c)}
+                                disabled={deletingId === c.pubkey}
+                                className="px-2 py-1 text-xs rounded bg-red-500/20 text-red-300 hover:bg-red-500/30 disabled:opacity-50"
+                              >
+                                {deletingId === c.pubkey ? 'Deleting…' : 'Confirm'}
+                              </button>
+                              <button
+                                onClick={() => setConfirmDelete(null)}
+                                className="px-2 py-1 text-xs rounded text-[#777] hover:text-slate-200"
+                              >
+                                Cancel
+                              </button>
+                            </>
+                          ) : (
+                            <button
+                              onClick={() => setConfirmDelete(c.pubkey)}
+                              className="p-1 rounded text-[#555] hover:text-red-400 hover:bg-red-500/10"
+                              title="Remove this contact from the companion"
+                            >
+                              <Trash2 size={13} />
+                            </button>
+                          )}
+                        </div>
                       </td>
                     </tr>
+                    {confirmDelete === c.pubkey && (
+                      <tr className="bg-red-500/5">
+                        <td colSpan={7} className="px-4 py-2 border-t border-red-500/20">
+                          <span className="text-xs text-red-300">
+                            Remove <span className="text-slate-100">{contactName(c)}</span>{' '}
+                            <span className="font-mono text-[11px]">{shortPubkey(c.pubkey)}</span>{' '}
+                            from the companion? It will only return if the node advertises again.
+                          </span>
+                        </td>
+                      </tr>
+                    )}
                     {hasReadout && (
                       <tr className="bg-[#0a0e17]/40">
                         <td colSpan={7} className="px-4 py-2 border-t border-border/50">
@@ -500,6 +1026,12 @@ export default function MeshCoreContacts() {
               })}
             </tbody>
           </table>
+          {visibleContacts.length === 0 && (
+            <div className="px-4 py-6 text-sm text-[#777]">
+              No contacts match this filter.
+            </div>
+          )}
+          </div>
         </div>
       )}
     </div>

work/meshai/config.py

@@ -59,6 +59,10 @@ class ConnectionConfig:
     meshcore_baud: int = 115200
     meshcore_ble_address: str = ""             # optional; for ble
     meshcore_auto_add_contacts: bool = True     # firmware auto-adds every node it hears an advert from (so AIDA can DM anyone)
+    # Refresh the cached roster whenever an advert/path-update is heard. Costs one
+    # incremental contact fetch to the companion per advert (local chatter, never a
+    # mesh send); false = lib default (connect-time snapshot + explicit resync only).
+    meshcore_auto_update_contacts: bool = True
     meshcore_ack_wait_seconds: float = 6.0       # wait for delivery ACK before falling back to path discovery
     meshcore_discovery_wait_seconds: float = 8.0  # path-discovery timeout on the no-ACK fallback (was hardcoded 25s)
 

work/meshai/dashboard/api/mesh_send_routes.py

@@ -1,16 +1,23 @@
 """Dashboard 'send test message' API routes (meshtastic + meshcore)."""
 
 import logging
-from datetime import datetime
+from datetime import datetime, timezone
 from typing import Optional, Union
 
 from fastapi import APIRouter, HTTPException, Request
+from fastapi.responses import JSONResponse
 from pydantic import BaseModel
 from meshai import secrets_store
+from meshai.meshcore_roster import check_route_health, find_name_collisions
 
 logger = logging.getLogger(__name__)
 router = APIRouter(tags=["mesh-send"])
 
+# Roster export envelope: identifies the file on the way back in so an import
+# can reject something that was never a meshai roster.
+_ROSTER_EXPORT_FORMAT = "meshai.meshcore.roster"
+_ROSTER_EXPORT_VERSION = 1
+
 
 def _find_child(connector, name: str):
     """Find a child transport by transport_name — handles bare transport or CompositeTransport."""
@@ -163,7 +170,12 @@ async def meshcore_rooms(request: Request):
 
 @router.get("/meshcore/contacts")
 async def meshcore_contacts(request: Request):
-    """Roster of known MeshCore contacts if a meshcore transport is connected."""
+    """Roster of known MeshCore contacts if a meshcore transport is connected.
+
+    ``last_synced_at`` (epoch seconds, or null) is when the roster was last
+    pulled from the companion, so the UI can present it as a snapshot with a
+    known age rather than implying it is live.
+    """
     connector = getattr(request.app.state, "connector", None)
     mc = _find_child(connector, "meshcore")
     if mc is not None and getattr(mc, "connected", False):
@@ -171,8 +183,253 @@ async def meshcore_contacts(request: Request):
             contacts = list(mc.get_contacts())
         except Exception:
             contacts = []
-        return {"active": True, "contacts": contacts}
-    return {"active": False, "contacts": []}
+        try:
+            last_synced_at = mc.contacts_synced_at()
+        except Exception:
+            last_synced_at = None
+        return {"active": True, "contacts": contacts, "last_synced_at": last_synced_at}
+    return {"active": False, "contacts": [], "last_synced_at": None}
+
+
+@router.post("/meshcore/contacts/refresh")
+async def meshcore_refresh_contacts(request: Request):
+    """Re-read the companion's device view — contacts AND channels.
+
+    meshai builds its picture of the device at connect and never re-reads it,
+    so a contact removed (or a channel provisioned) on the radio afterwards is
+    invisible until a restart. This is the resync path.
+
+    Unlike the passive roster read, the contact reconcile DROPS entries the
+    companion no longer has (the lib's own fetch only ever merges). Returns the
+    reconcile stats, the channel delta, and the refreshed roster + channel list.
+    """
+    connector = getattr(request.app.state, "connector", None)
+    mc = _find_child(connector, "meshcore")
+    if mc is None or not getattr(mc, "connected", False):
+        raise HTTPException(status_code=409, detail="MeshCore not connected")
+
+    try:
+        result = mc.resync()
+    except RuntimeError as exc:
+        raise HTTPException(status_code=502, detail=str(exc))
+    except Exception as exc:
+        logger.error("dashboard: meshcore resync error: %s", exc)
+        raise HTTPException(status_code=500, detail=str(exc))
+
+    stats = result.get("contacts", {})
+    channel_stats = result.get("channels", {})
+
+    try:
+        contacts = list(mc.get_contacts())
+    except Exception:
+        contacts = []
+    try:
+        channels = list(mc.known_channels())
+    except Exception:
+        channels = []
+    try:
+        last_synced_at = mc.contacts_synced_at()
+    except Exception:
+        last_synced_at = None
+
+    logger.info(
+        "dashboard: meshcore resync — contacts +%d/-%d (now %d), channels +%d/-%d",
+        stats.get("added", 0), stats.get("removed", 0), stats.get("after", 0),
+        len(channel_stats.get("added", [])), len(channel_stats.get("removed", [])),
+    )
+    return {
+        "active": True,
+        "stats": stats,
+        "channel_stats": channel_stats,
+        "contacts": contacts,
+        "channels": channels,
+        "last_synced_at": last_synced_at,
+    }
+
+
+@router.get("/meshcore/contacts/export")
+async def meshcore_export_contacts(request: Request):
+    """Download the roster as JSON.
+
+    Records carry the full lib field set (not the display projection), so an
+    export can be re-imported onto a replacement companion.
+    """
+    connector = getattr(request.app.state, "connector", None)
+    mc = _find_child(connector, "meshcore")
+    if mc is None or not getattr(mc, "connected", False):
+        raise HTTPException(status_code=409, detail="MeshCore not connected")
+
+    try:
+        records = mc.export_roster()
+    except Exception as exc:
+        logger.error("dashboard: meshcore export_roster error: %s", exc)
+        raise HTTPException(status_code=500, detail=str(exc))
+
+    try:
+        info = mc.self_info()
+    except Exception:
+        info = {}
+    try:
+        last_synced_at = mc.contacts_synced_at()
+    except Exception:
+        last_synced_at = None
+
+    payload = {
+        "format": _ROSTER_EXPORT_FORMAT,
+        "version": _ROSTER_EXPORT_VERSION,
+        "exported_at": datetime.now(timezone.utc).isoformat(),
+        "last_synced_at": last_synced_at,
+        # Which device this roster came off — a roster is only meaningful
+        # paired with the companion it was read from.
+        "device": {
+            "name": info.get("name"),
+            "pubkey": info.get("pubkey"),
+            "conn_type": info.get("conn_type"),
+            "target": info.get("target"),
+        },
+        "count": len(records),
+        "contacts": records,
+    }
+    filename = f"meshcore-roster-{datetime.now(timezone.utc).strftime('%Y%m%d-%H%M%S')}.json"
+    return JSONResponse(
+        content=payload,
+        headers={"Content-Disposition": f'attachment; filename="{filename}"'},
+    )
+
+
+class ImportContactsRequest(BaseModel):
+    contacts: list[dict]
+
+
+@router.post("/meshcore/contacts/import")
+async def meshcore_import_contacts(request: Request, body: ImportContactsRequest):
+    """Write exported roster records onto the companion.
+
+    Intended for migrating a roster to a replacement companion rather than
+    waiting to rediscover every node by advert. Additive and idempotent: each
+    record is an upsert, nothing is removed, and no mesh traffic is generated.
+
+    Per-record failures are collected rather than aborting the batch, so one bad
+    record cannot strand a partial import with no report of what landed.
+    """
+    connector = getattr(request.app.state, "connector", None)
+    mc = _find_child(connector, "meshcore")
+    if mc is None or not getattr(mc, "connected", False):
+        raise HTTPException(status_code=409, detail="MeshCore not connected")
+
+    records = body.contacts or []
+    if not records:
+        raise HTTPException(status_code=400, detail="No contacts supplied")
+
+    imported = 0
+    errors: list[dict] = []
+    for record in records:
+        try:
+            mc.import_contact(record)
+            imported += 1
+        except (ValueError, RuntimeError) as exc:
+            errors.append({"pubkey": record.get("pubkey"), "detail": str(exc)})
+        except Exception as exc:
+            logger.error("dashboard: meshcore import_contact error: %s", exc)
+            errors.append({"pubkey": record.get("pubkey"), "detail": str(exc)})
+
+    logger.info(
+        "dashboard: meshcore roster import — %d/%d written, %d failed",
+        imported, len(records), len(errors),
+    )
+    return {"active": True, "imported": imported, "failed": len(errors), "errors": errors}
+
+
+@router.delete("/meshcore/contacts/{pubkey}")
+async def meshcore_remove_contact(request: Request, pubkey: str):
+    """Remove a contact from the companion by full pubkey.
+
+    Requires the FULL 64-hex key — a prefix could match the wrong node, and a
+    wrongly-deleted contact is unrecoverable without rediscovery.
+    """
+    connector = getattr(request.app.state, "connector", None)
+    mc = _find_child(connector, "meshcore")
+    if mc is None or not getattr(mc, "connected", False):
+        raise HTTPException(status_code=409, detail="MeshCore not connected")
+
+    try:
+        mc.remove_contact(pubkey)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    except RuntimeError as exc:
+        raise HTTPException(status_code=502, detail=str(exc))
+    except Exception as exc:
+        logger.error("dashboard: meshcore remove_contact error: %s", exc)
+        raise HTTPException(status_code=500, detail=str(exc))
+
+    try:
+        contacts = list(mc.get_contacts())
+    except Exception:
+        contacts = []
+    logger.info("dashboard: meshcore contact %s removed", pubkey)
+    return {"active": True, "contacts": contacts}
+
+
+@router.get("/meshcore/route-health")
+async def meshcore_route_health(request: Request):
+    """Flag region-routing cells whose MeshCore target no longer exists.
+
+    Preventive: a cell pointing at a room pubkey or channel the companion does
+    not have will fail silently at send time — the alert is simply never
+    delivered, with nothing surfaced to the operator. Resolving every cell
+    up-front turns that silence into a visible warning. Read-only; sends nothing.
+
+    Also reports same-name/different-pubkey roster collisions, which are what
+    make a name-based picker ambiguous in the first place.
+
+    Returns {active, dangling, dangling_enabled, collisions, checked, mc_enabled}.
+    ``active: false`` (with empty results) when MeshCore is not connected — an
+    unreachable companion is not evidence that a route is broken.
+    """
+    connector = getattr(request.app.state, "connector", None)
+    mc = _find_child(connector, "meshcore")
+    if mc is None or not getattr(mc, "connected", False):
+        return {
+            "active": False,
+            "dangling": [],
+            "dangling_enabled": 0,
+            "collisions": [],
+            "checked": 0,
+            "mc_enabled": False,
+        }
+
+    config = getattr(request.app.state, "config", None)
+    rr = getattr(getattr(config, "notifications", None), "region_routes", None)
+    cells = getattr(rr, "cells", None) or {}
+    mc_enabled = bool(getattr(rr, "mc_enabled", False))
+
+    try:
+        contacts = list(mc.get_contacts())
+    except Exception:
+        contacts = []
+    try:
+        channels = list(mc.known_channels())
+    except Exception:
+        channels = []
+
+    dangling = check_route_health(cells, channels, contacts)
+    collisions = find_name_collisions(contacts)
+    checked = sum(
+        1
+        for regions in cells.values()
+        if isinstance(regions, dict)
+        for cell in regions.values()
+        if isinstance(cell, dict) and cell.get("mc")
+    )
+
+    return {
+        "active": True,
+        "dangling": dangling,
+        "dangling_enabled": sum(1 for d in dangling if d.get("enabled")),
+        "collisions": collisions,
+        "checked": checked,
+        "mc_enabled": mc_enabled,
+    }
 
 
 @router.get("/meshcore/self")

work/meshai/dashboard/static/index.html

@@ -8,8 +8,8 @@
     <link rel="preconnect" href="https://fonts.googleapis.com">
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
     <link href="https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600;700&display=swap" rel="stylesheet">
-    <script type="module" crossorigin src="/assets/index-BuD2nQeg.js"></script>
-    <link rel="stylesheet" crossorigin href="/assets/index-oCy31pjB.css">
+    <script type="module" crossorigin src="/assets/index-dwX3LKqm.js"></script>
+    <link rel="stylesheet" crossorigin href="/assets/index-CTVGSJxQ.css">
   </head>
   <body>
     <div id="root"></div>

work/meshai/meshcore_roster.py

@@ -0,0 +1,234 @@
+"""Pure roster helpers for the MeshCore companion: reconcile + route health.
+
+Deliberately free of device I/O and of the ``meshcore`` lib itself, so the two
+pieces of logic worth getting right — what a roster IS after a resync, and
+whether the routing matrix still points at destinations that exist — can be
+unit-tested without a radio.
+
+Two independent concerns live here:
+
+``reconcile_contacts``
+    Replace-semantics for a FULL contact refetch. The lib only ever merges
+    (see below), so this is what makes an operator-triggered resync able to
+    *drop* entries rather than only ever grow the roster.
+
+``check_route_health`` / ``find_name_collisions``
+    Read-only checks over the companion roster + the region-routing matrix.
+    Preventive: they answer "would this cell resolve if it fired right now?"
+    without sending anything.
+"""
+
+from typing import Any, Optional
+
+# MeshCore contact.type as reported by the firmware CONTACT_TYPENAMES table
+# [NONE, CLI, REP, ROOM, SENS]. Mirrors MeshCoreTransport.ROOM_CONTACT_TYPE.
+ROOM_CONTACT_TYPE = 3
+
+
+def reconcile_contacts(
+    cached: dict[str, dict], fresh: dict[str, dict]
+) -> tuple[dict[str, dict], dict[str, Any]]:
+    """Reconcile a cached roster against a FULL refetch, with replace semantics.
+
+    The meshcore lib's contact handler (``meshcore/meshcore.py::_update_contacts``)
+    only ever ``.update()``s existing entries or adds new ones — it has no
+    removal path. So merging a fetch into the cache can never shrink it: an
+    entry removed on the companion would persist in the cache until reconnect.
+    Reconciling against an authoritative full fetch restores replace semantics:
+    anything absent from *fresh* is dropped.
+
+    Per-contact FIELDS are merged (fresh wins) rather than replaced wholesale,
+    which keeps the lib's field-merge behavior for contacts that still exist —
+    a fresh record missing an optional field must not blank the cached one.
+
+    IMPORTANT — the caller must only pass a *fresh* that came from a SUCCESSFUL
+    full fetch (``get_contacts(lastmod=0)`` returning a CONTACTS event). This
+    function trusts *fresh* as authoritative: an empty *fresh* legitimately
+    means "the companion has no contacts" and will empty the roster. Passing a
+    partial/failed fetch here would silently delete real contacts.
+
+    Args:
+        cached: pubkey -> contact dict (the lib's current mirror).
+        fresh:  pubkey -> contact dict (authoritative FULL fetch).
+
+    Returns:
+        (reconciled, stats). ``stats`` carries before/after/added/removed/updated
+        counts plus ``added_keys``/``removed_keys`` (sorted pubkey lists) so the
+        caller can report exactly what a resync changed.
+    """
+    reconciled: dict[str, dict] = {}
+    added: list[str] = []
+    updated: list[str] = []
+
+    for pubkey, contact in fresh.items():
+        previous = cached.get(pubkey)
+        if previous is None:
+            reconciled[pubkey] = dict(contact)
+            added.append(pubkey)
+            continue
+        merged = {**previous, **contact}
+        reconciled[pubkey] = merged
+        if merged != previous:
+            updated.append(pubkey)
+
+    removed = [pubkey for pubkey in cached if pubkey not in fresh]
+
+    stats: dict[str, Any] = {
+        "before": len(cached),
+        "after": len(reconciled),
+        "added": len(added),
+        "removed": len(removed),
+        "updated": len(updated),
+        "added_keys": sorted(added),
+        "removed_keys": sorted(removed),
+    }
+    return reconciled, stats
+
+
+def _find_contact_by_key_prefix(
+    contacts: list[dict], prefix: str
+) -> Optional[dict]:
+    """Resolve *prefix* to a contact the way the send path does.
+
+    Mirrors ``meshcore.MeshCore.get_contact_by_key_prefix``: case-insensitive
+    ``startswith`` on the contact's pubkey. Room routing cells are resolved
+    through that same call (``MeshCoreTransport._resolve_contact``), so the
+    health check MUST use identical matching or it would report a cell as
+    dangling that the dispatcher can in fact resolve (a 12-hex prefix from the
+    room picker is a legitimate cell value, not just a full key).
+    """
+    if not prefix:
+        return None
+    needle = prefix.lower()
+    for contact in contacts:
+        pubkey = (contact.get("pubkey") or "").lower()
+        if pubkey.startswith(needle):
+            return contact
+    return None
+
+
+def check_route_health(
+    cells: dict,
+    channel_names: list[str],
+    contacts: list[dict],
+) -> list[dict]:
+    """Flag region-routing cells whose MeshCore target does not exist.
+
+    Preventive check — it resolves each cell's ``mc`` target against the live
+    companion roster/channel table and reports the ones that would not resolve.
+    Nothing is sent.
+
+    A cell's ``mc`` value is either ``room:<pubkey>`` (addressed room send) or a
+    bare channel NAME; the parse is delegated to the single canonical
+    implementation in ``meshai.notifications.channels`` so this can never drift
+    from what the dispatcher actually does.
+
+    Cells with no ``mc`` target are skipped (nothing to resolve). Disabled cells
+    ARE still checked and returned with ``enabled: False`` — a broken cell is
+    worth surfacing before someone re-enables it — so callers should weight the
+    enabled ones when deciding how loudly to complain.
+
+    Args:
+        cells: ``region_routes.cells`` — family -> region -> cell dict.
+        channel_names: channel NAMES on the companion (``known_channels()``).
+        contacts: roster dicts with at least ``pubkey``/``name``/``type``.
+
+    Returns:
+        A list of offending cells, each
+        ``{family, region, target, kind, reason, enabled}``. Empty list = healthy.
+    """
+    # Lazy import: keeps this module dependency-free at import time and avoids
+    # pulling the notifications stack (httpx/smtplib) into transport callers.
+    from meshai.notifications.channels import parse_meshcore_room  # noqa: PLC0415
+
+    known = {name for name in channel_names}
+    problems: list[dict] = []
+
+    for family, regions in (cells or {}).items():
+        if not isinstance(regions, dict):
+            continue
+        for region, cell in regions.items():
+            if not isinstance(cell, dict):
+                continue
+            target = cell.get("mc")
+            if not target or not isinstance(target, str):
+                continue
+            enabled = bool(cell.get("enabled", True))
+
+            room_pubkey = parse_meshcore_room(target)
+            if room_pubkey is not None:
+                contact = _find_contact_by_key_prefix(contacts, room_pubkey)
+                if contact is None:
+                    problems.append({
+                        "family": family,
+                        "region": region,
+                        "target": target,
+                        "kind": "room",
+                        "reason": "room_not_found",
+                        "enabled": enabled,
+                    })
+                elif contact.get("type") != ROOM_CONTACT_TYPE:
+                    # Resolves to a real contact that is not a room server —
+                    # an addressed send would go to the wrong kind of node.
+                    problems.append({
+                        "family": family,
+                        "region": region,
+                        "target": target,
+                        "kind": "room",
+                        "reason": "not_a_room",
+                        "enabled": enabled,
+                    })
+                continue
+
+            if target not in known:
+                problems.append({
+                    "family": family,
+                    "region": region,
+                    "target": target,
+                    "kind": "channel",
+                    "reason": "channel_not_found",
+                    "enabled": enabled,
+                })
+
+    return problems
+
+
+def find_name_collisions(contacts: list[dict]) -> list[dict]:
+    """Group roster entries that share a name but have different pubkeys.
+
+    A name is not a stable identifier on MeshCore — two operators can advertise
+    the same ``adv_name`` from different keypairs. Anything that picks a target
+    by name alone (a room picker, an operator reading a table) cannot tell them
+    apart, so surfacing the collision is what makes the ambiguity visible.
+
+    Only same-name/different-pubkey groups are returned; duplicates of the same
+    pubkey are not a collision.
+
+    Returns:
+        ``[{name, count, contacts: [{pubkey, type}, ...]}]``, sorted by name.
+        Empty list = no collisions.
+    """
+    by_name: dict[str, dict[str, dict]] = {}
+    for contact in contacts:
+        name = contact.get("name")
+        if not name:
+            continue
+        pubkey = contact.get("pubkey") or ""
+        if not pubkey:
+            continue
+        by_name.setdefault(name, {})[pubkey] = contact
+
+    collisions: list[dict] = []
+    for name, keyed in by_name.items():
+        if len(keyed) < 2:
+            continue
+        collisions.append({
+            "name": name,
+            "count": len(keyed),
+            "contacts": [
+                {"pubkey": pubkey, "type": c.get("type")}
+                for pubkey, c in sorted(keyed.items())
+            ],
+        })
+
+    return sorted(collisions, key=lambda c: c["name"])

work/meshai/transport/meshcore_transport.py

@@ -21,6 +21,7 @@ from typing import Callable, Optional
 from .base import MeshTransport
 from .send_queue import RadioSendQueue
 from ..connector import MeshMessage
+from ..meshcore_roster import reconcile_contacts
 
 logger = logging.getLogger(__name__)
 
@@ -123,6 +124,10 @@ class MeshCoreTransport(MeshTransport):
         self._chan_details: list[dict] = []
         # Self-advertisement tracking.
         self._last_advert_sent: Optional[float] = None   # epoch seconds or None
+        # When the contact roster was last synced from the companion (epoch
+        # seconds): set at connect and on every refresh_contacts(). Lets the
+        # dashboard show roster freshness rather than implying "live".
+        self._contacts_synced_at: Optional[float] = None
         # asyncio.Task handle for the periodic advert loop; None when inactive.
         self._advert_task = None
         # asyncio.Task handle for the telemetry auto-poll loop; None when inactive.
@@ -146,6 +151,48 @@ class MeshCoreTransport(MeshTransport):
     # Internal helpers
     # ------------------------------------------------------------------
 
+    def _connection_descriptor(self) -> dict:
+        """Describe the CONFIGURED connection: how we attach to the companion.
+
+        Single source of truth for both the connect() log line and the
+        ``self_info()`` API payload, so the two can never disagree about which
+        device meshai is attached to. Exactly one transport's fields are
+        populated per ``conn_type``; the rest are None. ``target`` is the
+        human-readable form ("serial:/dev/x@115200", "host:port", "ble:addr").
+
+        Reads config only — it describes the configured attachment, not a live
+        handle, so it is safe to call before connect() and while disconnected.
+        """
+        conn_type = (getattr(self.config, "meshcore_conn_type", "tcp") or "tcp").strip().lower()
+        base = {
+            "conn_type": conn_type,
+            "host": None,
+            "port": None,
+            "serial_port": None,
+            "baud": None,
+            "ble_address": None,
+        }
+        if conn_type == "serial":
+            serial_port = getattr(self.config, "meshcore_serial_port", "") or ""
+            baud = getattr(self.config, "meshcore_baud", 115200)
+            base.update({
+                "serial_port": serial_port or None,
+                "baud": baud,
+                "target": f"serial:{serial_port}@{baud}",
+            })
+            return base
+        if conn_type == "ble":
+            ble_address = getattr(self.config, "meshcore_ble_address", "") or ""
+            base.update({
+                "ble_address": ble_address or None,
+                "target": f"ble:{ble_address or 'auto'}",
+            })
+            return base
+        host = getattr(self.config, "meshcore_host", "") or ""
+        port = getattr(self.config, "meshcore_port", 5050)
+        base.update({"host": host or None, "port": port, "target": f"{host}:{port}"})
+        return base
+
     def _run_coro(self, coro, timeout: float = _COMMAND_TIMEOUT):
         """Submit *coro* to the dedicated event loop and block until done.
 
@@ -991,6 +1038,238 @@ class MeshCoreTransport(MeshTransport):
             })
         return roster
 
+    def contacts_synced_at(self) -> Optional[float]:
+        """Epoch seconds when the roster was last synced from the companion."""
+        return self._contacts_synced_at
+
+    async def _refresh_contacts_async(self) -> dict:
+        """Force a FULL contact refetch and reconcile the lib's cache. Runs on the MC loop.
+
+        ``ensure_contacts()`` is a no-op once the cache is populated, and even
+        when it does fetch it passes ``lastmod`` (incremental). Neither path can
+        ever shrink the cache, because the lib's CONTACTS handler only merges.
+        This forces ``get_contacts(lastmod=0)`` — the authoritative FULL set —
+        and then REPLACES the cache with it, so entries the companion no longer
+        has are dropped rather than surviving forever.
+
+        Only reconciles on a successful CONTACTS event: an ERROR/timeout leaves
+        the cache untouched, because treating a failed fetch as authoritative
+        would delete the entire roster.
+
+        Returns the reconcile stats dict (before/after/added/removed/updated).
+        """
+        from meshcore import EventType  # noqa: PLC0415 (lazy import intentional)
+
+        mc = self._mc
+        if mc is None:
+            raise RuntimeError("MeshCore not connected")
+
+        result = await mc.commands.get_contacts(lastmod=0)
+        if result is None:
+            raise RuntimeError("contact refresh failed: no response from companion")
+        if getattr(result, "type", None) == EventType.ERROR:
+            reason = (getattr(result, "payload", None) or {}).get("reason", "unknown")
+            raise RuntimeError(f"contact refresh failed: {reason}")
+
+        payload = getattr(result, "payload", None) or {}
+        # Re-key by public_key to match the lib's own cache layout — the event
+        # payload may be keyed differently, but every value carries its key.
+        fresh: dict[str, dict] = {}
+        for contact in payload.values():
+            if not isinstance(contact, dict):
+                continue
+            pubkey = contact.get("public_key")
+            if pubkey:
+                fresh[pubkey] = contact
+
+        cached = dict(getattr(mc, "contacts", None) or {})
+        reconciled, stats = reconcile_contacts(cached, fresh)
+
+        # Replace the lib's cache in place. The lib exposes ``contacts`` as a
+        # read-only property over ``_contacts``, so the private attr is the only
+        # way to apply removals; assigning a fresh dict would also break the
+        # lib's own handlers that mutate it in place.
+        mc._contacts.clear()
+        mc._contacts.update(reconciled)
+        mc._contacts_dirty = False
+
+        self._contacts_synced_at = _time.time()
+        logger.info(
+            "MeshCore: roster resync — %d before, %d after (+%d added, -%d removed, %d updated)",
+            stats["before"], stats["after"], stats["added"], stats["removed"], stats["updated"],
+        )
+        return stats
+
+    def refresh_contacts(self) -> dict:
+        """Force a FULL roster resync from the companion and reconcile the cache.
+
+        Blocking wrapper around ``_refresh_contacts_async``. Raises RuntimeError
+        when not connected or when the companion fetch fails. Returns the
+        reconcile stats dict.
+        """
+        if self._mc is None or not self._connected:
+            raise RuntimeError("MeshCore not connected")
+        return self._run_coro(self._refresh_contacts_async(), timeout=30.0)
+
+    def resync(self) -> dict:
+        """Re-read the companion's full device view: contacts AND channels.
+
+        meshai's picture of the device is otherwise built once at connect —
+        contacts by ``ensure_contacts()``, channels by ``_enumerate_channels()``
+        — and never re-read. A channel provisioned on the radio afterwards is
+        invisible until the process restarts. This is the one operator action
+        that re-reads both.
+
+        Must be called OFF the MC loop (it bridges through ``_run_coro``); the
+        dashboard route thread is the intended caller.
+
+        Returns ``{"contacts": <reconcile stats>, "channels": {before, after,
+        added, removed}}``.
+        """
+        if self._mc is None or not self._connected:
+            raise RuntimeError("MeshCore not connected")
+
+        contact_stats = self.refresh_contacts()
+
+        # Channels: re-walk the companion's slot table. _enumerate_channels()
+        # rebuilds BOTH _chan_name_to_idx and _chan_details (the async variant
+        # only does the former, which would leave the Channels view stale).
+        before = set(self.known_channels())
+        self._enumerate_channels()
+        after = set(self.known_channels())
+        channel_stats = {
+            "before": len(before),
+            "after": len(after),
+            "added": sorted(after - before),
+            "removed": sorted(before - after),
+        }
+        if channel_stats["added"] or channel_stats["removed"]:
+            logger.info(
+                "MeshCore: channel resync — +%s / -%s",
+                channel_stats["added"], channel_stats["removed"],
+            )
+        return {"contacts": contact_stats, "channels": channel_stats}
+
+    def remove_contact(self, pubkey: str) -> None:
+        """Remove a contact from the companion by full pubkey.
+
+        Wraps the lib's ``commands.remove_contact`` (CMD 0x0f). The lib does not
+        touch its own cache on removal, so the entry is dropped from the mirror
+        here too — otherwise the deleted contact would reappear in the roster
+        until the next full resync.
+
+        A FULL 64-hex pubkey is required: the lib validates with
+        ``prefix_length=32``, and a prefix could otherwise resolve to the wrong
+        node — the wrong contact silently deleted. Raises ValueError on a bad
+        key, RuntimeError when not connected or when the companion rejects it.
+        """
+        if self._mc is None or not self._connected:
+            raise RuntimeError("MeshCore not connected")
+        key = (pubkey or "").strip().lower()
+        if len(key) != 64:
+            raise ValueError("A full 64-character hex pubkey is required to remove a contact")
+        try:
+            bytes.fromhex(key)
+        except ValueError:
+            raise ValueError(f"Invalid pubkey hex: {pubkey!r}")
+
+        from meshcore import EventType  # noqa: PLC0415 (lazy import intentional)
+
+        result = self._run_coro(self._mc.commands.remove_contact(key), timeout=15.0)
+        if result is None:
+            raise RuntimeError("remove_contact failed: no response from companion")
+        if getattr(result, "type", None) == EventType.ERROR:
+            reason = (getattr(result, "payload", None) or {}).get("reason", "unknown")
+            raise RuntimeError(f"remove_contact failed: {reason}")
+
+        try:
+            self._mc._contacts.pop(key, None)
+        except Exception:
+            logger.debug("MeshCore: could not drop %s from cache mirror", key, exc_info=True)
+        logger.info("MeshCore: removed contact %s from companion", key)
+
+    def export_roster(self) -> list[dict]:
+        """Roster as importable records: the raw lib fields, not the UI view.
+
+        ``get_contacts()`` returns a display projection; a record has to carry
+        every field ``commands.update_contact`` writes back (type, flags, the
+        out_path triplet, adv_name, last_advert, adv_lat/adv_lon) or it cannot
+        be imported onto another companion. Returns [] when not connected.
+        """
+        if self._mc is None or not self._connected:
+            return []
+        contacts = getattr(self._mc, "contacts", None) or {}
+        records: list[dict] = []
+        for pubkey_hex, contact in contacts.items():
+            if not isinstance(contact, dict):
+                continue
+            pubkey = contact.get("public_key") or pubkey_hex
+            try:
+                out_path_len = int(contact.get("out_path_len", -1))
+            except (TypeError, ValueError):
+                out_path_len = -1
+            records.append({
+                "name": contact.get("adv_name"),
+                "pubkey": pubkey,
+                "type": contact.get("type"),
+                "flags": contact.get("flags"),
+                "last_advert": contact.get("last_advert"),
+                "adv_lat": contact.get("adv_lat"),
+                "adv_lon": contact.get("adv_lon"),
+                "out_path": contact.get("out_path"),
+                "out_path_len": out_path_len,
+                "out_path_hash_mode": contact.get("out_path_hash_mode"),
+                "path_established": out_path_len >= 0,
+            })
+        return sorted(records, key=lambda r: (r["name"] or "").lower())
+
+    def import_contact(self, record: dict) -> None:
+        """Write one exported roster record onto the companion.
+
+        Uses ``commands.add_contact`` (which delegates to ``update_contact``,
+        CMD 0x09) to rebuild a contact on a replacement companion without
+        waiting to rediscover it by advert. This is a LOCAL device write — it
+        does not transmit to the mesh.
+
+        Additive/idempotent by nature: CMD 0x09 upserts, so re-importing an
+        existing contact overwrites that record rather than duplicating it.
+        Raises ValueError on a malformed record, RuntimeError on rejection.
+        """
+        if self._mc is None or not self._connected:
+            raise RuntimeError("MeshCore not connected")
+        pubkey = (record.get("pubkey") or "").strip().lower()
+        if len(pubkey) != 64:
+            raise ValueError("Each contact needs a full 64-character hex pubkey")
+        try:
+            bytes.fromhex(pubkey)
+        except ValueError:
+            raise ValueError(f"Invalid pubkey hex: {pubkey!r}")
+
+        # Rebuild the lib-shaped contact dict update_contact() expects. The
+        # defaults keep a hand-written or older export importable: an unknown
+        # path simply means "flood until a path is discovered".
+        contact = {
+            "public_key": pubkey,
+            "type": int(record.get("type") or 0),
+            "flags": int(record.get("flags") or 0),
+            "out_path": record.get("out_path") or "",
+            "out_path_len": int(record.get("out_path_len", -1) if record.get("out_path_len") is not None else -1),
+            "out_path_hash_mode": int(record.get("out_path_hash_mode") or 0),
+            "adv_name": record.get("name") or "",
+            "last_advert": int(record.get("last_advert") or 0),
+            "adv_lat": float(record.get("adv_lat") or 0.0),
+            "adv_lon": float(record.get("adv_lon") or 0.0),
+        }
+
+        from meshcore import EventType  # noqa: PLC0415 (lazy import intentional)
+
+        result = self._run_coro(self._mc.commands.add_contact(contact), timeout=15.0)
+        if result is None:
+            raise RuntimeError("import_contact failed: no response from companion")
+        if getattr(result, "type", None) == EventType.ERROR:
+            reason = (getattr(result, "payload", None) or {}).get("reason", "unknown")
+            raise RuntimeError(f"import_contact failed: {reason}")
+
     # A MeshCore ROOM SERVER is a contact whose ``type`` is ROOM (3) in the
     # firmware CONTACT_TYPENAMES table [NONE, CLI, REP, ROOM, SENS]. We route
     # to a room via the DM primitive (send_msg to its pubkey), so a room is
@@ -1106,18 +1385,34 @@ class MeshCoreTransport(MeshTransport):
         return await self._do_mc_dm_send_async(text, pubkey)
 
     def self_info(self) -> dict:
-        """Companion self/connection status. {connected: False} if not connected."""
+        """Companion self/connection status. {connected: False} if not connected.
+
+        ``name``/``pubkey`` identify the ACTUAL connected device; the connection
+        fields describe how we are attached to it. Only the fields belonging to
+        the live ``conn_type`` are populated — the others are None. Reporting
+        ``host``/``port`` unconditionally (as this did previously) meant a serial
+        connection still advertised whatever stale ``meshcore_host`` sat in the
+        config, i.e. the API named a device meshai was not talking to. Anyone
+        trusting that pointer investigates the wrong physical radio.
+        """
         if self._mc is None or not self._connected:
             return {"connected": False}
         info = self._self_info or {}
+        descriptor = self._connection_descriptor()
         return {
             "name": info.get("name"),
             "pubkey": info.get("public_key"),
             "connected": True,
-            "host": getattr(self.config, "meshcore_host", "100.64.0.9"),
-            "port": getattr(self.config, "meshcore_port", 5050),
+            "conn_type": descriptor["conn_type"],
+            "target": descriptor["target"],
+            "host": descriptor["host"],
+            "port": descriptor["port"],
+            "serial_port": descriptor["serial_port"],
+            "baud": descriptor["baud"],
+            "ble_address": descriptor["ble_address"],
             "channel_count": len(self.known_channels()),
             "last_advert_sent": self._last_advert_sent,
+            "contacts_synced_at": self._contacts_synced_at,
         }
 
     def set_context_config(self, cfg) -> None:
@@ -1532,8 +1827,28 @@ class MeshCoreTransport(MeshTransport):
         self._mc.subscribe(EventType.NEW_CONTACT, self._on_new_contact)
         try:
             await self._mc.ensure_contacts()
+            self._contacts_synced_at = _time.time()
         except Exception:
             logger.debug("MeshCore: ensure_contacts failed (non-fatal)", exc_info=True)
+
+        # Let the lib refresh its roster when it hears an ADVERTISEMENT /
+        # PATH_UPDATE. The lib defaults this OFF, which leaves the roster a
+        # connect-time snapshot that only grows (its CONTACTS handler merges and
+        # never removes) until something forces a refetch.
+        #
+        # TRADE-OFF: each advert heard costs one incremental get_contacts()
+        # round-trip to the companion — local serial/TCP chatter, never a mesh
+        # transmission. On a dense mesh (and especially with
+        # meshcore_auto_add_contacts, where the firmware adds every node it
+        # hears) that is a steady trickle of fetches. Set
+        # meshcore_auto_update_contacts=false to keep the lib default and rely
+        # on the explicit "Resync" action instead.
+        if getattr(self.config, "meshcore_auto_update_contacts", True):
+            try:
+                self._mc.auto_update_contacts = True
+                logger.info("MeshCore: auto-update-contacts ENABLED (adverts refresh the roster)")
+            except Exception as exc:
+                logger.warning("MeshCore: could not enable auto_update_contacts (non-fatal): %s", exc)
         if getattr(self.config, "meshcore_auto_add_contacts", True):
             try:
                 await self._mc.commands.set_autoadd_config(1)
@@ -1571,13 +1886,9 @@ class MeshCoreTransport(MeshTransport):
         auto_reconnect = getattr(self.config, "meshcore_auto_reconnect", True)
         max_attempts = getattr(self.config, "meshcore_max_reconnect_attempts", 5)
 
-        # Build a human-readable target string for logging.
-        if conn_type == "serial":
-            target = f"serial:{serial_port}@{baud}"
-        elif conn_type == "ble":
-            target = f"ble:{ble_address or 'auto'}"
-        else:
-            target = f"{host}:{port}"
+        # Human-readable target for logging — from the same descriptor that
+        # self_info() reports, so the log and the API never disagree.
+        target = self._connection_descriptor()["target"]
 
         logger.info("MeshCoreTransport: connecting to %s …", target)
 

work/tests/test_mesh_send_api.py

@@ -6,6 +6,7 @@ Uses a bare FastAPI() + TestClient with a hand-seeded ``app.state.connector``
 """
 from __future__ import annotations
 
+from types import SimpleNamespace
 from unittest.mock import AsyncMock, MagicMock
 
 import pytest
@@ -198,12 +199,17 @@ _SAMPLE_ROSTER = [
 def test_meshcore_contacts_active():
     mc = _child("meshcore", connected=True)
     mc.get_contacts.return_value = list(_SAMPLE_ROSTER)
+    mc.contacts_synced_at.return_value = 1700000000.0
     connector = _composite([mc])
     client = _client(connector)
 
     r = client.get("/api/meshcore/contacts")
     assert r.status_code == 200
-    assert r.json() == {"active": True, "contacts": _SAMPLE_ROSTER}
+    assert r.json() == {
+        "active": True,
+        "contacts": _SAMPLE_ROSTER,
+        "last_synced_at": 1700000000.0,
+    }
 
 
 def test_meshcore_contacts_no_meshcore():
@@ -213,7 +219,7 @@ def test_meshcore_contacts_no_meshcore():
 
     r = client.get("/api/meshcore/contacts")
     assert r.status_code == 200
-    assert r.json() == {"active": False, "contacts": []}
+    assert r.json() == {"active": False, "contacts": [], "last_synced_at": None}
 
 
 def test_meshcore_contacts_disconnected():
@@ -223,7 +229,250 @@ def test_meshcore_contacts_disconnected():
 
     r = client.get("/api/meshcore/contacts")
     assert r.status_code == 200
-    assert r.json() == {"active": False, "contacts": []}
+    assert r.json() == {"active": False, "contacts": [], "last_synced_at": None}
+
+
+# ============================================================================
+# POST /api/meshcore/contacts/refresh — full resync + reconcile
+# ============================================================================
+
+_REFRESH_STATS = {
+    "before": 3, "after": 3, "added": 1, "removed": 1, "updated": 0,
+    "added_keys": ["cc" * 32], "removed_keys": ["bb" * 32],
+}
+
+
+_CHANNEL_STATS = {"before": 4, "after": 5, "added": ["#new-chan"], "removed": []}
+
+
+def test_meshcore_refresh_returns_contact_and_channel_stats():
+    """The resync re-reads BOTH halves of the device view, and reports each."""
+    mc = _child("meshcore", connected=True, known=["#aida", "#new-chan"])
+    mc.resync.return_value = {"contacts": dict(_REFRESH_STATS), "channels": dict(_CHANNEL_STATS)}
+    mc.get_contacts.return_value = list(_SAMPLE_ROSTER)
+    mc.contacts_synced_at.return_value = 1700000000.0
+    client = _client(_composite([mc]))
+
+    r = client.post("/api/meshcore/contacts/refresh")
+
+    assert r.status_code == 200
+    body = r.json()
+    assert body["stats"] == _REFRESH_STATS
+    assert body["channel_stats"] == _CHANNEL_STATS
+    assert body["contacts"] == _SAMPLE_ROSTER
+    assert body["channels"] == ["#aida", "#new-chan"]
+    assert body["last_synced_at"] == 1700000000.0
+    mc.resync.assert_called_once()
+
+
+def test_meshcore_refresh_conflict_when_disconnected():
+    mc = _child("meshcore", connected=False)
+    client = _client(_composite([mc]))
+
+    r = client.post("/api/meshcore/contacts/refresh")
+
+    assert r.status_code == 409
+    mc.resync.assert_not_called()
+
+
+def test_meshcore_refresh_surfaces_companion_failure():
+    """A failed fetch must surface, not be reported as a successful resync."""
+    mc = _child("meshcore", connected=True)
+    mc.resync.side_effect = RuntimeError("contact refresh failed: timeout")
+    client = _client(_composite([mc]))
+
+    r = client.post("/api/meshcore/contacts/refresh")
+
+    assert r.status_code == 502
+    assert "timeout" in r.json()["detail"]
+
+
+# ============================================================================
+# DELETE /api/meshcore/contacts/{pubkey}
+# ============================================================================
+
+def test_meshcore_delete_contact_removes_and_returns_roster():
+    mc = _child("meshcore", connected=True)
+    mc.get_contacts.return_value = list(_SAMPLE_ROSTER)
+    client = _client(_composite([mc]))
+
+    r = client.delete(f"/api/meshcore/contacts/{'aa' * 32}")
+
+    assert r.status_code == 200
+    assert r.json() == {"active": True, "contacts": _SAMPLE_ROSTER}
+    mc.remove_contact.assert_called_once_with("aa" * 32)
+
+
+def test_meshcore_delete_contact_rejects_bad_key():
+    mc = _child("meshcore", connected=True)
+    mc.remove_contact.side_effect = ValueError("A full 64-character hex pubkey is required")
+    client = _client(_composite([mc]))
+
+    r = client.delete("/api/meshcore/contacts/aa11")
+
+    assert r.status_code == 400
+
+
+def test_meshcore_delete_contact_conflict_when_disconnected():
+    mc = _child("meshcore", connected=False)
+    client = _client(_composite([mc]))
+
+    r = client.delete(f"/api/meshcore/contacts/{'aa' * 32}")
+
+    assert r.status_code == 409
+    mc.remove_contact.assert_not_called()
+
+
+# ============================================================================
+# GET /api/meshcore/contacts/export
+# ============================================================================
+
+def test_meshcore_export_returns_envelope_and_attachment():
+    mc = _child("meshcore", connected=True)
+    mc.export_roster.return_value = [{"name": "N", "pubkey": "aa" * 32, "type": 1}]
+    mc.self_info.return_value = {
+        "name": "AIDA", "pubkey": "a6" * 32,
+        "conn_type": "serial", "target": "serial:/dev/meshcore-rak@115200",
+    }
+    mc.contacts_synced_at.return_value = 1700000000.0
+    client = _client(_composite([mc]))
+
+    r = client.get("/api/meshcore/contacts/export")
+
+    assert r.status_code == 200
+    assert "attachment" in r.headers["content-disposition"]
+    body = r.json()
+    assert body["format"] == "meshai.meshcore.roster"
+    assert body["count"] == 1
+    # The roster is only meaningful paired with the device it came from.
+    assert body["device"]["conn_type"] == "serial"
+    assert body["device"]["target"] == "serial:/dev/meshcore-rak@115200"
+
+
+def test_meshcore_export_conflict_when_disconnected():
+    mc = _child("meshcore", connected=False)
+    client = _client(_composite([mc]))
+
+    assert client.get("/api/meshcore/contacts/export").status_code == 409
+
+
+# ============================================================================
+# POST /api/meshcore/contacts/import
+# ============================================================================
+
+def test_meshcore_import_writes_each_record():
+    mc = _child("meshcore", connected=True)
+    client = _client(_composite([mc]))
+
+    r = client.post("/api/meshcore/contacts/import", json={
+        "contacts": [{"pubkey": "aa" * 32}, {"pubkey": "bb" * 32}],
+    })
+
+    assert r.status_code == 200
+    assert r.json() == {"active": True, "imported": 2, "failed": 0, "errors": []}
+    assert mc.import_contact.call_count == 2
+
+
+def test_meshcore_import_collects_per_record_errors():
+    """One bad record must not strand the batch with no report of what landed."""
+    mc = _child("meshcore", connected=True)
+    mc.import_contact.side_effect = [None, ValueError("bad pubkey")]
+    client = _client(_composite([mc]))
+
+    r = client.post("/api/meshcore/contacts/import", json={
+        "contacts": [{"pubkey": "aa" * 32}, {"pubkey": "nope"}],
+    })
+
+    body = r.json()
+    assert body["imported"] == 1
+    assert body["failed"] == 1
+    assert body["errors"][0]["pubkey"] == "nope"
+
+
+def test_meshcore_import_rejects_empty_payload():
+    mc = _child("meshcore", connected=True)
+    client = _client(_composite([mc]))
+
+    assert client.post("/api/meshcore/contacts/import", json={"contacts": []}).status_code == 400
+
+
+# ============================================================================
+# GET /api/meshcore/route-health
+# ============================================================================
+
+def _config_with_cells(cells, mc_enabled=True):
+    return SimpleNamespace(
+        notifications=SimpleNamespace(
+            region_routes=SimpleNamespace(mt_enabled=True, mc_enabled=mc_enabled, cells=cells)
+        )
+    )
+
+
+def _health_client(connector, config):
+    app = FastAPI()
+    app.include_router(router, prefix="/api")
+    app.state.connector = connector
+    app.state.config = config
+    return TestClient(app)
+
+
+def test_route_health_flags_dangling_room_cell():
+    mc = _child("meshcore", connected=True, known=["#aida"])
+    mc.get_contacts.return_value = []
+    config = _config_with_cells({"fire": {"SC Idaho": {"mc": f"room:{'de' * 32}", "enabled": True}}})
+    client = _health_client(_composite([mc]), config)
+
+    body = client.get("/api/meshcore/route-health").json()
+
+    assert body["active"] is True
+    assert len(body["dangling"]) == 1
+    assert body["dangling"][0]["reason"] == "room_not_found"
+    assert body["dangling_enabled"] == 1
+
+
+def test_route_health_clean_when_targets_resolve():
+    mc = _child("meshcore", connected=True, known=["#aida"])
+    mc.get_contacts.return_value = [
+        {"pubkey": "aa" * 32, "name": "Room", "type": 3},
+    ]
+    config = _config_with_cells({
+        "weather": {
+            "SW Idaho": {"mc": "#aida", "enabled": True},
+            "SC Idaho": {"mc": f"room:{'aa' * 32}", "enabled": True},
+        }
+    })
+    client = _health_client(_composite([mc]), config)
+
+    body = client.get("/api/meshcore/route-health").json()
+
+    assert body["dangling"] == []
+    assert body["checked"] == 2
+
+
+def test_route_health_reports_name_collisions():
+    mc = _child("meshcore", connected=True, known=[])
+    mc.get_contacts.return_value = [
+        {"pubkey": "aa" * 32, "name": "SC ID AIDA Alerts", "type": 3},
+        {"pubkey": "bb" * 32, "name": "SC ID AIDA Alerts", "type": 3},
+    ]
+    client = _health_client(_composite([mc]), _config_with_cells({}))
+
+    body = client.get("/api/meshcore/route-health").json()
+
+    assert len(body["collisions"]) == 1
+    assert body["collisions"][0]["count"] == 2
+
+
+def test_route_health_inactive_when_disconnected():
+    """A disconnected companion is not evidence that a route is broken."""
+    mc = _child("meshcore", connected=False)
+    config = _config_with_cells({"fire": {"SC Idaho": {"mc": "room:dead", "enabled": True}}})
+    client = _health_client(_composite([mc]), config)
+
+    body = client.get("/api/meshcore/route-health").json()
+
+    assert body["active"] is False
+    assert body["dangling"] == []
 
 
 # ============================================================================

work/tests/test_meshcore_roster.py

@@ -0,0 +1,714 @@
+"""Tests for MeshCore roster management: reconcile, route health, name collisions.
+
+Covers:
+  - reconcile_contacts(): full-refetch replace semantics (the crux — a merge
+    can never remove, so this is what lets a resync drop stale entries)
+  - check_route_health(): region-routing cells pointing at absent rooms/channels
+  - find_name_collisions(): same name, different pubkey
+  - MeshCoreTransport.self_info(): reports the ACTUAL connection, never a
+    config value belonging to a different conn_type
+  - MeshCoreTransport._refresh_contacts_async / remove_contact / import_contact
+
+The companion is mocked throughout: no device I/O, no mesh traffic, nothing
+removed from a real radio.
+"""
+
+import asyncio
+import sys
+import types
+
+import pytest
+
+from meshai.meshcore_roster import (
+    check_route_health,
+    find_name_collisions,
+    reconcile_contacts,
+)
+
+
+# ---------------------------------------------------------------------------
+# Helpers
+# ---------------------------------------------------------------------------
+
+def _contact(pubkey: str, name: str = "node", type_: int = 1, **extra) -> dict:
+    """A lib-shaped contact dict (public_key is the lib's key field)."""
+    base = {
+        "public_key": pubkey,
+        "adv_name": name,
+        "type": type_,
+        "last_advert": 1000,
+        "out_path_len": -1,
+        "out_path": "",
+        "out_path_hash_mode": 0,
+        "flags": 0,
+        "adv_lat": 0.0,
+        "adv_lon": 0.0,
+    }
+    base.update(extra)
+    return base
+
+
+def _roster(pubkey: str, name: str = "node", type_: int = 1) -> dict:
+    """A roster-projection contact dict (as get_contacts() returns)."""
+    return {"pubkey": pubkey, "name": name, "type": type_, "last_advert": 1000}
+
+
+KEY_A = "aa" * 32
+KEY_B = "bb" * 32
+KEY_C = "cc" * 32
+
+
+# ---------------------------------------------------------------------------
+# Part 1: reconcile_contacts — replace semantics
+# ---------------------------------------------------------------------------
+
+class TestReconcileContacts:
+    def test_absent_contact_is_dropped(self):
+        """The crux: a contact missing from the FULL refetch is removed.
+
+        The lib's own fetch handler only merges, so without this a deleted
+        contact survives in the cache forever.
+        """
+        cached = {KEY_A: _contact(KEY_A, "alpha"), KEY_B: _contact(KEY_B, "bravo")}
+        fresh = {KEY_A: _contact(KEY_A, "alpha")}
+
+        reconciled, stats = reconcile_contacts(cached, fresh)
+
+        assert KEY_B not in reconciled
+        assert set(reconciled) == {KEY_A}
+        assert stats["removed"] == 1
+        assert stats["removed_keys"] == [KEY_B]
+        assert stats["before"] == 2
+        assert stats["after"] == 1
+
+    def test_new_contact_is_added(self):
+        cached = {KEY_A: _contact(KEY_A, "alpha")}
+        fresh = {KEY_A: _contact(KEY_A, "alpha"), KEY_B: _contact(KEY_B, "bravo")}
+
+        reconciled, stats = reconcile_contacts(cached, fresh)
+
+        assert set(reconciled) == {KEY_A, KEY_B}
+        assert stats["added"] == 1
+        assert stats["added_keys"] == [KEY_B]
+        assert stats["removed"] == 0
+
+    def test_changed_contact_is_updated(self):
+        cached = {KEY_A: _contact(KEY_A, "alpha", last_advert=1000)}
+        fresh = {KEY_A: _contact(KEY_A, "alpha", last_advert=2000)}
+
+        reconciled, stats = reconcile_contacts(cached, fresh)
+
+        assert reconciled[KEY_A]["last_advert"] == 2000
+        assert stats["updated"] == 1
+        assert stats["added"] == 0
+        assert stats["removed"] == 0
+
+    def test_unchanged_contact_not_counted_as_updated(self):
+        cached = {KEY_A: _contact(KEY_A, "alpha")}
+        fresh = {KEY_A: _contact(KEY_A, "alpha")}
+
+        _, stats = reconcile_contacts(cached, fresh)
+
+        assert stats["updated"] == 0
+        assert stats["added"] == 0
+        assert stats["removed"] == 0
+        assert stats["after"] == 1
+
+    def test_fields_merge_rather_than_replace(self):
+        """A fresh record missing an optional field must not blank the cached one."""
+        cached = {KEY_A: _contact(KEY_A, "alpha", nickname="local-only")}
+        fresh = {KEY_A: {"public_key": KEY_A, "adv_name": "alpha-renamed"}}
+
+        reconciled, _ = reconcile_contacts(cached, fresh)
+
+        assert reconciled[KEY_A]["adv_name"] == "alpha-renamed"   # fresh wins
+        assert reconciled[KEY_A]["nickname"] == "local-only"      # survives
+        assert reconciled[KEY_A]["type"] == 1                     # survives
+
+    def test_add_remove_and_update_together(self):
+        cached = {
+            KEY_A: _contact(KEY_A, "alpha", last_advert=1000),
+            KEY_B: _contact(KEY_B, "bravo"),
+        }
+        fresh = {
+            KEY_A: _contact(KEY_A, "alpha", last_advert=2000),
+            KEY_C: _contact(KEY_C, "charlie"),
+        }
+
+        reconciled, stats = reconcile_contacts(cached, fresh)
+
+        assert set(reconciled) == {KEY_A, KEY_C}
+        assert (stats["added"], stats["removed"], stats["updated"]) == (1, 1, 1)
+        assert stats["added_keys"] == [KEY_C]
+        assert stats["removed_keys"] == [KEY_B]
+
+    def test_empty_fresh_empties_roster(self):
+        """An authoritative full fetch of zero contacts means zero contacts.
+
+        Guarding this would mean a genuinely-wiped companion could never be
+        reflected; the caller is responsible for only passing a SUCCESSFUL fetch.
+        """
+        cached = {KEY_A: _contact(KEY_A), KEY_B: _contact(KEY_B)}
+
+        reconciled, stats = reconcile_contacts(cached, {})
+
+        assert reconciled == {}
+        assert stats["removed"] == 2
+        assert stats["after"] == 0
+
+    def test_empty_cache_adds_everything(self):
+        fresh = {KEY_A: _contact(KEY_A), KEY_B: _contact(KEY_B)}
+
+        reconciled, stats = reconcile_contacts({}, fresh)
+
+        assert set(reconciled) == {KEY_A, KEY_B}
+        assert stats["added"] == 2
+        assert stats["before"] == 0
+
+    def test_does_not_mutate_inputs(self):
+        cached = {KEY_A: _contact(KEY_A, "alpha", last_advert=1000)}
+        fresh = {KEY_B: _contact(KEY_B, "bravo")}
+        cached_snapshot = {KEY_A: dict(cached[KEY_A])}
+
+        reconcile_contacts(cached, fresh)
+
+        assert cached == cached_snapshot   # caller's cache untouched
+        assert set(fresh) == {KEY_B}
+
+    def test_merge_semantics_alone_can_never_remove(self):
+        """Contrast: the lib's merge keeps a stale entry that reconcile drops.
+
+        Documents exactly what the reconcile adds over the lib's behavior.
+        """
+        cached = {KEY_A: _contact(KEY_A), KEY_B: _contact(KEY_B)}
+        fresh = {KEY_A: _contact(KEY_A)}
+
+        merged = dict(cached)
+        merged.update(fresh)                    # what the lib does
+        reconciled, _ = reconcile_contacts(cached, fresh)   # what we do
+
+        assert KEY_B in merged                  # stale entry survives a merge
+        assert KEY_B not in reconciled          # ...and is dropped by reconcile
+
+
+# ---------------------------------------------------------------------------
+# Part 2: check_route_health — dangling routing cells
+# ---------------------------------------------------------------------------
+
+class TestCheckRouteHealth:
+    CHANNELS = ["Public", "#aida", "#sw-id-aida"]
+
+    def test_healthy_cells_report_nothing(self):
+        cells = {
+            "weather": {
+                "SW Idaho": {"mc": "#sw-id-aida", "enabled": True},
+                "SC Idaho": {"mc": f"room:{KEY_A}", "enabled": True},
+            }
+        }
+        contacts = [_roster(KEY_A, "SC Room", type_=3)]
+
+        assert check_route_health(cells, self.CHANNELS, contacts) == []
+
+    def test_cell_pointing_at_missing_room_is_flagged(self):
+        cells = {"weather": {"SC Idaho": {"mc": f"room:{KEY_B}", "enabled": True}}}
+        contacts = [_roster(KEY_A, "SC Room", type_=3)]
+
+        problems = check_route_health(cells, self.CHANNELS, contacts)
+
+        assert len(problems) == 1
+        assert problems[0]["family"] == "weather"
+        assert problems[0]["region"] == "SC Idaho"
+        assert problems[0]["kind"] == "room"
+        assert problems[0]["reason"] == "room_not_found"
+        assert problems[0]["enabled"] is True
+
+    def test_cell_pointing_at_missing_channel_is_flagged(self):
+        cells = {"fire": {"East Idaho": {"mc": "#e-id-aida", "enabled": True}}}
+
+        problems = check_route_health(cells, self.CHANNELS, [])
+
+        assert len(problems) == 1
+        assert problems[0]["kind"] == "channel"
+        assert problems[0]["reason"] == "channel_not_found"
+        assert problems[0]["target"] == "#e-id-aida"
+
+    def test_room_cell_resolving_to_non_room_is_flagged(self):
+        """A room cell that resolves to a plain node would address the wrong kind."""
+        cells = {"weather": {"SC Idaho": {"mc": f"room:{KEY_A}", "enabled": True}}}
+        contacts = [_roster(KEY_A, "Just A Node", type_=1)]
+
+        problems = check_route_health(cells, self.CHANNELS, contacts)
+
+        assert len(problems) == 1
+        assert problems[0]["reason"] == "not_a_room"
+
+    def test_room_cell_matches_by_prefix(self):
+        """The send path resolves rooms by pubkey PREFIX — so must this check.
+
+        A 12-hex prefix (what the room picker stores) is a legitimate cell
+        value; treating it as dangling would be a false alarm.
+        """
+        cells = {"weather": {"SC Idaho": {"mc": f"room:{KEY_A[:12]}", "enabled": True}}}
+        contacts = [_roster(KEY_A, "SC Room", type_=3)]
+
+        assert check_route_health(cells, self.CHANNELS, contacts) == []
+
+    def test_room_prefix_match_is_case_insensitive(self):
+        cells = {"weather": {"SC Idaho": {"mc": f"room:{KEY_A[:12].upper()}", "enabled": True}}}
+        contacts = [_roster(KEY_A, "SC Room", type_=3)]
+
+        assert check_route_health(cells, self.CHANNELS, contacts) == []
+
+    def test_disabled_cell_still_reported_but_marked(self):
+        cells = {"weather": {"SC Idaho": {"mc": f"room:{KEY_B}", "enabled": False}}}
+
+        problems = check_route_health(cells, self.CHANNELS, [])
+
+        assert len(problems) == 1
+        assert problems[0]["enabled"] is False
+
+    def test_cell_without_mc_target_is_skipped(self):
+        cells = {"weather": {"SW Idaho": {"mt": 3, "mc": None, "enabled": True}}}
+
+        assert check_route_health(cells, self.CHANNELS, []) == []
+
+    def test_empty_room_pubkey_treated_as_channel_name(self):
+        """``room:`` with no pubkey is not a room target (parser yields None)."""
+        cells = {"weather": {"SC Idaho": {"mc": "room:", "enabled": True}}}
+
+        problems = check_route_health(cells, self.CHANNELS, [])
+
+        assert len(problems) == 1
+        assert problems[0]["kind"] == "channel"
+
+    def test_empty_cells_and_missing_families(self):
+        assert check_route_health({}, self.CHANNELS, []) == []
+        assert check_route_health({"weather": None}, self.CHANNELS, []) == []
+
+    def test_multiple_families_and_regions(self):
+        cells = {
+            "weather": {
+                "SW Idaho": {"mc": "#sw-id-aida", "enabled": True},   # healthy
+                "SC Idaho": {"mc": f"room:{KEY_B}", "enabled": True},  # dangling
+            },
+            "fire": {
+                "East Idaho": {"mc": "#gone", "enabled": True},        # dangling
+            },
+        }
+        contacts = [_roster(KEY_A, "SC Room", type_=3)]
+
+        problems = check_route_health(cells, self.CHANNELS, contacts)
+
+        assert len(problems) == 2
+        assert {p["reason"] for p in problems} == {"room_not_found", "channel_not_found"}
+
+
+# ---------------------------------------------------------------------------
+# Part 3: find_name_collisions
+# ---------------------------------------------------------------------------
+
+class TestFindNameCollisions:
+    def test_same_name_different_pubkey_is_a_collision(self):
+        contacts = [
+            _roster(KEY_A, "SC ID AIDA Alerts", type_=3),
+            _roster(KEY_B, "SC ID AIDA Alerts", type_=3),
+        ]
+
+        collisions = find_name_collisions(contacts)
+
+        assert len(collisions) == 1
+        assert collisions[0]["name"] == "SC ID AIDA Alerts"
+        assert collisions[0]["count"] == 2
+        assert {c["pubkey"] for c in collisions[0]["contacts"]} == {KEY_A, KEY_B}
+
+    def test_distinct_names_are_not_collisions(self):
+        contacts = [_roster(KEY_A, "SC ID AIDA"), _roster(KEY_B, "SC ID AIDA Alerts")]
+
+        assert find_name_collisions(contacts) == []
+
+    def test_same_pubkey_twice_is_not_a_collision(self):
+        contacts = [_roster(KEY_A, "dup"), _roster(KEY_A, "dup")]
+
+        assert find_name_collisions(contacts) == []
+
+    def test_unnamed_contacts_ignored(self):
+        contacts = [_roster(KEY_A, None), _roster(KEY_B, None)]
+
+        assert find_name_collisions(contacts) == []
+
+    def test_empty_roster(self):
+        assert find_name_collisions([]) == []
+
+
+# ---------------------------------------------------------------------------
+# Part 4: transport — self_info() connection reporting
+# ---------------------------------------------------------------------------
+
+@pytest.fixture
+def fake_meshcore(monkeypatch):
+    """Register a fake ``meshcore`` module for the lazy imports in the transport.
+
+    monkeypatch.setitem (not sys.modules.setdefault) so this wins even when the
+    real lib — or another test module's fake — is already imported, and is
+    restored afterwards.
+    """
+    mod = types.ModuleType("meshcore")
+
+    class EventType:
+        ERROR = "ERROR"
+        CONTACTS = "CONTACTS"
+        OK = "OK"
+
+    mod.EventType = EventType
+    monkeypatch.setitem(sys.modules, "meshcore", mod)
+    return mod
+
+
+class _Event:
+    def __init__(self, type_, payload=None):
+        self.type = type_
+        self.payload = payload or {}
+
+
+class _FakeCommands:
+    """Records calls; returns whatever the test queues up."""
+
+    def __init__(self):
+        self.get_contacts_calls = []
+        self.removed = []
+        self.added = []
+        self.get_contacts_result = None
+        self.remove_result = _Event("OK")
+        self.add_result = _Event("OK")
+
+    async def get_contacts(self, lastmod=0, timeout=5):
+        self.get_contacts_calls.append(lastmod)
+        return self.get_contacts_result
+
+    async def remove_contact(self, key):
+        self.removed.append(key)
+        return self.remove_result
+
+    async def add_contact(self, contact):
+        self.added.append(contact)
+        return self.add_result
+
+
+class _FakeMC:
+    def __init__(self, contacts=None):
+        self._contacts = dict(contacts or {})
+        self._contacts_dirty = True
+        self._lastmod = 500
+        self.commands = _FakeCommands()
+        self.auto_update_contacts = False
+
+    @property
+    def contacts(self):
+        return self._contacts
+
+
+def _transport(**cfg_kwargs):
+    """Build a transport with a fake MC attached and marked connected."""
+    from meshai.config import ConnectionConfig
+    from meshai.transport.meshcore_transport import MeshCoreTransport
+
+    transport = MeshCoreTransport(ConnectionConfig(**cfg_kwargs))
+    return transport
+
+
+class TestSelfInfoConnectionReporting:
+    """self_info() must describe the ACTUAL connection, never a stale config value."""
+
+    def test_serial_does_not_report_config_host(self):
+        """The bug: a serial connection reporting a leftover meshcore_host.
+
+        meshcore_host/port are never read on the serial path, so surfacing them
+        names a device meshai is not talking to — which is what sends an
+        investigation to the wrong physical radio.
+        """
+        t = _transport(
+            meshcore_conn_type="serial",
+            meshcore_serial_port="/dev/meshcore-rak",
+            meshcore_baud=115200,
+            # A stale TCP host left in config from a previous companion:
+            meshcore_host="192.168.1.253",
+            meshcore_port=5050,
+        )
+        t._mc = _FakeMC()
+        t._connected = True
+        t._self_info = {"name": "AIDA", "public_key": KEY_A}
+
+        info = t.self_info()
+
+        assert info["conn_type"] == "serial"
+        assert info["serial_port"] == "/dev/meshcore-rak"
+        assert info["baud"] == 115200
+        assert info["target"] == "serial:/dev/meshcore-rak@115200"
+        # The stale host must NOT be surfaced:
+        assert info["host"] is None
+        assert info["port"] is None
+        # Identity still comes from the real device:
+        assert info["name"] == "AIDA"
+        assert info["pubkey"] == KEY_A
+
+    def test_tcp_reports_host_and_port(self):
+        t = _transport(
+            meshcore_conn_type="tcp",
+            meshcore_host="100.64.0.9",
+            meshcore_port=5050,
+        )
+        t._mc = _FakeMC()
+        t._connected = True
+        t._self_info = {"name": "TCPNode", "public_key": KEY_B}
+
+        info = t.self_info()
+
+        assert info["conn_type"] == "tcp"
+        assert info["host"] == "100.64.0.9"
+        assert info["port"] == 5050
+        assert info["target"] == "100.64.0.9:5050"
+        assert info["serial_port"] is None
+        assert info["baud"] is None
+
+    def test_ble_reports_address_only(self):
+        t = _transport(
+            meshcore_conn_type="ble",
+            meshcore_ble_address="AA:BB:CC:DD:EE:FF",
+            meshcore_host="192.168.1.253",
+        )
+        t._mc = _FakeMC()
+        t._connected = True
+        t._self_info = {"name": "BleNode", "public_key": KEY_C}
+
+        info = t.self_info()
+
+        assert info["conn_type"] == "ble"
+        assert info["ble_address"] == "AA:BB:CC:DD:EE:FF"
+        assert info["target"] == "ble:AA:BB:CC:DD:EE:FF"
+        assert info["host"] is None
+        assert info["port"] is None
+
+    def test_not_connected_reports_only_connected_false(self):
+        t = _transport(meshcore_conn_type="serial", meshcore_serial_port="/dev/x")
+
+        assert t.self_info() == {"connected": False}
+
+    def test_descriptor_matches_connect_log_target(self):
+        """connect() and self_info() must never disagree about the target."""
+        t = _transport(
+            meshcore_conn_type="serial",
+            meshcore_serial_port="/dev/meshcore-rak",
+            meshcore_baud=115200,
+        )
+        t._mc = _FakeMC()
+        t._connected = True
+        t._self_info = {}
+
+        assert t.self_info()["target"] == t._connection_descriptor()["target"]
+
+
+# ---------------------------------------------------------------------------
+# Part 5: transport — refresh / remove / import against a mocked companion
+# ---------------------------------------------------------------------------
+
+class TestRefreshContactsAsync:
+    def test_full_refetch_uses_lastmod_zero_and_reconciles(self, fake_meshcore):
+        """The resync must be FULL (lastmod=0), not the lib's incremental fetch.
+
+        An incremental fetch cannot see a contact whose last_advert predates
+        _lastmod, and merging its result could never drop the stale KEY_B.
+        """
+        t = _transport(meshcore_conn_type="serial", meshcore_serial_port="/dev/x")
+        mc = _FakeMC({KEY_A: _contact(KEY_A, "alpha"), KEY_B: _contact(KEY_B, "bravo")})
+        mc.commands.get_contacts_result = _Event(
+            "CONTACTS", {KEY_A: _contact(KEY_A, "alpha"), KEY_C: _contact(KEY_C, "charlie")}
+        )
+        t._mc = mc
+        t._connected = True
+
+        stats = asyncio.run(t._refresh_contacts_async())
+
+        assert mc.commands.get_contacts_calls == [0]        # FULL, not _lastmod
+        assert set(mc._contacts) == {KEY_A, KEY_C}          # cache replaced in place
+        assert stats["removed"] == 1 and stats["added"] == 1
+        assert t._contacts_synced_at is not None
+
+    def test_payload_rekeyed_by_public_key(self, fake_meshcore):
+        """The event payload may be keyed by anything; the cache is by pubkey."""
+        t = _transport()
+        mc = _FakeMC()
+        mc.commands.get_contacts_result = _Event(
+            "CONTACTS", {"some-other-key": _contact(KEY_A, "alpha")}
+        )
+        t._mc = mc
+        t._connected = True
+
+        asyncio.run(t._refresh_contacts_async())
+
+        assert set(mc._contacts) == {KEY_A}
+
+    def test_error_event_leaves_cache_untouched(self, fake_meshcore):
+        """A failed fetch must never be treated as authoritative — that would
+        delete the entire roster."""
+        t = _transport()
+        mc = _FakeMC({KEY_A: _contact(KEY_A), KEY_B: _contact(KEY_B)})
+        mc.commands.get_contacts_result = _Event("ERROR", {"reason": "timeout"})
+        t._mc = mc
+        t._connected = True
+
+        with pytest.raises(RuntimeError, match="timeout"):
+            asyncio.run(t._refresh_contacts_async())
+
+        assert set(mc._contacts) == {KEY_A, KEY_B}   # intact
+
+    def test_no_response_raises(self, fake_meshcore):
+        t = _transport()
+        mc = _FakeMC({KEY_A: _contact(KEY_A)})
+        mc.commands.get_contacts_result = None
+        t._mc = mc
+        t._connected = True
+
+        with pytest.raises(RuntimeError, match="no response"):
+            asyncio.run(t._refresh_contacts_async())
+
+        assert set(mc._contacts) == {KEY_A}
+
+    def test_cache_object_identity_preserved(self, fake_meshcore):
+        """The lib mutates _contacts in place; replacing the dict would orphan it."""
+        t = _transport()
+        mc = _FakeMC({KEY_B: _contact(KEY_B)})
+        original = mc._contacts
+        mc.commands.get_contacts_result = _Event("CONTACTS", {KEY_A: _contact(KEY_A)})
+        t._mc = mc
+        t._connected = True
+
+        asyncio.run(t._refresh_contacts_async())
+
+        assert mc._contacts is original
+
+
+class TestResync:
+    """resync() must re-read BOTH halves of the connect-time device view.
+
+    Channels are enumerated once at connect (_enumerate_channels) and never
+    re-read, so a channel provisioned on the radio afterwards stays invisible
+    until the process restarts — the resync is the only path that picks it up.
+    """
+
+    def _transport_with_loop(self):
+        """A transport whose _run_coro works (real loop, fake device)."""
+        import threading
+
+        t = _transport(meshcore_conn_type="serial", meshcore_serial_port="/dev/x")
+        mc = _FakeMC({KEY_A: _contact(KEY_A, "alpha"), KEY_B: _contact(KEY_B, "bravo")})
+        mc.commands.get_contacts_result = _Event("CONTACTS", {KEY_A: _contact(KEY_A, "alpha")})
+        t._mc = mc
+        t._connected = True
+        t._loop = asyncio.new_event_loop()
+        threading.Thread(
+            target=lambda: (asyncio.set_event_loop(t._loop), t._loop.run_forever()),
+            daemon=True,
+        ).start()
+        for _ in range(50):
+            if t._loop.is_running():
+                break
+            __import__("time").sleep(0.02)
+        return t, mc
+
+    def test_resync_reports_contact_and_channel_deltas(self, fake_meshcore, monkeypatch):
+        t, mc = self._transport_with_loop()
+        try:
+            t._chan_name_to_idx = {"#aida": 1, "#old": 2}
+
+            # Stand in for the companion's channel table on re-enumeration:
+            # #old is gone, #new appeared.
+            def fake_enumerate():
+                t._chan_name_to_idx = {"#aida": 1, "#new": 3}
+
+            monkeypatch.setattr(t, "_enumerate_channels", fake_enumerate)
+
+            result = t.resync()
+
+            assert result["contacts"]["removed"] == 1          # KEY_B dropped
+            assert result["channels"]["added"] == ["#new"]
+            assert result["channels"]["removed"] == ["#old"]
+            assert result["channels"]["before"] == 2
+            assert result["channels"]["after"] == 2
+        finally:
+            t._loop.call_soon_threadsafe(t._loop.stop)
+
+    def test_resync_raises_when_not_connected(self):
+        with pytest.raises(RuntimeError, match="not connected"):
+            _transport().resync()
+
+
+class TestRemoveContact:
+    def test_rejects_prefix_requiring_full_key(self):
+        """A prefix could match the wrong node — and a wrong delete is permanent."""
+        t = _transport()
+        t._mc = _FakeMC()
+        t._connected = True
+
+        with pytest.raises(ValueError, match="full 64-character"):
+            t.remove_contact(KEY_A[:12])
+
+    def test_rejects_non_hex(self):
+        t = _transport()
+        t._mc = _FakeMC()
+        t._connected = True
+
+        with pytest.raises(ValueError, match="Invalid pubkey hex"):
+            t.remove_contact("z" * 64)
+
+    def test_raises_when_not_connected(self):
+        t = _transport()
+
+        with pytest.raises(RuntimeError, match="not connected"):
+            t.remove_contact(KEY_A)
+
+
+class TestImportContact:
+    def test_rejects_record_without_full_pubkey(self):
+        t = _transport()
+        t._mc = _FakeMC()
+        t._connected = True
+
+        with pytest.raises(ValueError, match="full 64-character"):
+            t.import_contact({"pubkey": "abcd", "name": "x"})
+
+    def test_raises_when_not_connected(self):
+        t = _transport()
+
+        with pytest.raises(RuntimeError, match="not connected"):
+            t.import_contact({"pubkey": KEY_A})
+
+
+class TestExportRoster:
+    def test_export_carries_importable_fields(self):
+        """An export missing the update_contact field set cannot be re-imported."""
+        t = _transport()
+        t._mc = _FakeMC({KEY_A: _contact(KEY_A, "alpha", out_path_len=2, out_path="abcd")})
+        t._connected = True
+
+        records = t.export_roster()
+
+        assert len(records) == 1
+        record = records[0]
+        for field in (
+            "name", "pubkey", "type", "flags", "last_advert",
+            "adv_lat", "adv_lon", "out_path", "out_path_len", "out_path_hash_mode",
+        ):
+            assert field in record
+        assert record["pubkey"] == KEY_A
+        assert record["name"] == "alpha"
+        assert record["path_established"] is True
+
+    def test_export_marks_flood_only_contact(self):
+        t = _transport()
+        t._mc = _FakeMC({KEY_A: _contact(KEY_A, "alpha", out_path_len=-1)})
+        t._connected = True
+
+        assert t.export_roster()[0]["path_established"] is False
+
+    def test_export_empty_when_not_connected(self):
+        assert _transport().export_roster() == []