v0.10.10: new avalanche_org adapter — backcountry avalanche advisories (#98)

meshai-requested adapter for avalanche.org's per-center map layers (SNFAC
Sawtooth + PAC Payette by default; operator-extensible to any avalanche.org
forecast center). Pure passthrough + severity gate, no cross-source fusion,
fits Central's adapter pattern cleanly.

Adapter surface:
- Polls https://api.avalanche.org/v2/public/products/map-layer/{center_id}
  per configured center; default cadence 1800s (30 min).
- Severity gate: only danger_level >= 3 publishes. danger_level 0/1/2
  (None/Low/Moderate), -1 ('no rating'), and off_season=true all omitted at
  adapter level. Idaho summer = all 4 SNFAC + 2 PAC zones yield 0 events;
  that's correct behavior, verified by the negative-case test against the
  frozen 2026-06-08 SNFAC fixture.
- Severity mapping (corrected from meshai's inverted spec): danger_level
  3 (Considerable) → severity 2, 4 (High) → 3, 5 (Extreme) → 4. Matches
  Central's 4-most-severe convention (nws.SEVERITY_MAP).
- Subject: central.avy.advisory.us.{state_lower} — one per state; v0.10.8's
  category-discriminated Nats-Msg-Id keeps multiple zones in the same state
  from colliding in JetStream dedup.
- Stream: CENTRAL_AVY (central.avy.>); 7-day / 1 GiB retention defaults.
- Event.data fields per meshai spec: center_id, zone_name, danger_level,
  danger_name, travel_advice (truncated to 200 chars), state, valid_date,
  end_date, off_season=false, latitude/longitude (polygon centroid via
  shapely), plus geo.geometry passes through as the upstream Polygon.

Tests (38 in test_avalanche_org.py):
- Pure helpers: _slug (8 cases), _parse_iso (6 cases), _centroid (2 cases).
- Severity gate: 3 publish cases (danger 3/4/5 → severity 2/3/4),
  4 omit cases (danger -1/0/1/2), off_season=true omit, missing state omit,
  unparseable geom omit, travel_advice truncation, subject derivation.
- Real-fixture negative case: 4-zone SNFAC fixture all omitted off-season.
- Real-fixture positive case: same fixture with synthetic winter overrides
  publishes all 4 with valid centroids on actual Idaho polygons.
- End-to-end poll() with mixed severities and the new wiring (streams
  registry + supervisor family map).
- Defensive: empty center_ids list yields nothing without crashing.

Wiring + plumbing:
- src/central/streams.py: StreamEntry('CENTRAL_AVY', 'central.avy.>')
- src/central/supervisor.py: STREAM_CATEGORY_DOMAINS['CENTRAL_AVY']=('avy',)
- sql/migrations/035: seed config.streams row (mirror of 019/CENTRAL_SPACE,
  idempotent ON CONFLICT DO NOTHING). Note: migrations don't auto-run on
  supervisor restart -- see deferred ops list (schema_migrations cleanup
  blocks central-migrate from running anything cleanly).
- src/central/gui/templates/_event_rows/avalanche_org.html (8 lines)
- src/central/gui/templates/_event_summaries/avalanche_org.html (2 lines)
  Both required by the existing per-adapter template consistency tests.

Doc updates (required by existing doc-vs-registry tests):
- docs/PRODUCER-INTEGRATION.md §6.1: added 'avy' to top-level-domain list.
- docs/PRODUCER-INTEGRATION.md §8: added StreamEntry('CENTRAL_AVY',...) line
  to the verbatim snippet.
- docs/CONSUMER-INTEGRATION.md §3 stream layout table: added CENTRAL_AVY row.
- docs/CONSUMER-INTEGRATION.md §6: new '### avalanche_org' subsection with
  source, subject convention, dedup key, severity gate, Event.data field
  table, and off-season behavior note.
- tests/test_events_feed_frontend.py: added avalanche_org to _SAMPLE_INNER
  and _EXPECTED_SUBJECT (the events-JSON subject-derivation coverage tests).

Budget note: this PR is well over the ~400-line target -- the new-adapter
surface picked up downstream consistency tests (doc validators + frontend
sample coverage + template partials) I didn't anticipate at probe time.
Most of the overrun is the SNFAC fixture (1,135 lines pretty-printed JSON,
non-code) and the adapter + tests pair. Stripping the fixture and the
required doc/template edits would leave ~620 lines of code; the fixture
itself is a frozen snapshot, not a maintenance burden.

Full sweep: 1072 passed, 0 failures (+41 from this PR), ruff clean on
all new files. One PRE-EXISTING ruff violation in supervisor.py (unused
poll_start variable at line 388) surfaces when we touch supervisor.py;
confirmed not introduced by this PR via git stash check.

Deploy plan (NEW STREAM — archive restart required per
[[feedback_new_stream_needs_archive_restart]]):
1. Squash-merge -> tag v0.10.10 -> push.
2. On central: pull main -> systemctl restart central-supervisor -> ALSO
   systemctl restart central-archive (new event-bearing stream; archive
   enumerates consumers at startup and doesn't hot-reload).
3. Migration 035 deferred to morning per the schema_migrations cleanup
   task -- the stream creation itself doesn't depend on it (supervisor
   creates JetStream streams from the STREAMS registry at startup; the
   config.streams row is for operator-tunable retention only).
4. Verify: nats stream info CENTRAL_AVY (created), poll log shows
   yielded=0 / omitted=N (off-season), no positive publishes during
   summer (correct).

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docs/CONSUMER-INTEGRATION.md

@@ -134,6 +134,7 @@ Central's archive.
 | `CENTRAL_TRAFFIC` | `central.traffic.>` | 7 | 1 GiB | ✓ | ✓ |
 | `CENTRAL_TRAFFIC_FLOW` | `central.traffic_flow.>` | 7 | 1 GiB | ✓ | ✓ |
 | `CENTRAL_TRAFFIC_CAMERAS` | `central.traffic_cameras.>` | 7 | 1 GiB | ✓ | ✓ |
+| `CENTRAL_AVY` | `central.avy.>` | 7 | 1 GiB | ✓ | ✓ |
 | `CENTRAL_META` | `central.meta.>` | 1 | 1 GiB | — | ✓ |
 
 Retention and storage caps are migration-seeded defaults visible in `config.streams`;
@@ -1791,6 +1792,45 @@ at parameter `00060`, gage height (ft) at `00065`, water temperature (°C) at
 \
 ---
 
+### avalanche_org — avalanche.org backcountry advisories (v0.10.10)
+
+- **Source:** `https://api.avalanche.org/v2/public/products/map-layer/<center_id>`
+  per configured forecast center (defaults: SNFAC Sawtooth, PAC Payette).
+- **Stream:** `CENTRAL_AVY` (`central.avy.>`)
+- **Subject:** `central.avy.advisory.us.<state_lower>` — one subject per state;
+  multiple zones in the same state coexist via category-discriminated
+  `Nats-Msg-Id` (v0.10.8).
+- **Dedup key shape:** `<center_id>_<zone_name_slug>` (e.g. `SNFAC_banner_summit`).
+  Slug is the zone name lowercased with non-alphanumeric runs collapsed to `_`.
+- **Severity gate (adapter-side):** only `danger_level >= 3` publishes.
+  `danger_level` of 0/1/2 (None/Low/Moderate), -1 ("no rating"), and
+  `off_season=true` are all omitted — no Event yielded.
+- **Severity mapping (danger_level → Event.severity / centralseverity):**
+  `3 (Considerable) → 2`, `4 (High) → 3`, `5 (Extreme) → 4`. Higher = more
+  severe per Central convention.
+- **Event.data fields:**
+
+  | Field | Type | Notes |
+  |---|---|---|
+  | `center_id` | string | Upstream forecast center identifier (e.g. `SNFAC`) |
+  | `zone_name` | string | Human-readable zone name (e.g. `Banner Summit`) |
+  | `danger_level` | int | 3, 4, or 5 (published levels only) |
+  | `danger_name` | string | Upstream textual label (`Considerable`/`High`/`Extreme`) |
+  | `travel_advice` | string | Truncated to 200 chars |
+  | `state` | string | 2-letter state code (uppercase) |
+  | `valid_date` | string | Upstream `start_date` ISO string (timezone-naive) |
+  | `end_date` | string | Upstream `end_date` ISO string |
+  | `off_season` | bool | Always `false` for published events |
+  | `latitude` / `longitude` | float | Polygon centroid (computed via shapely) |
+- **Geometry:** the upstream Polygon passes through as-is in `geo.geometry`.
+  MultiPolygon also supported defensively; centroid is computed from whichever.
+- **Off-season behavior:** during summer all SNFAC/PAC zones return
+  `off_season=true` + `danger_level=-1` — the adapter yields zero events,
+  by design.
+
+\
+---
+
 ## 7. Fall-off / removal semantics
 
 Central adapters fall into three buckets for handling upstream events that