feat(central): v0.4 C.1 Central connector backend (no-op until adapter source flipped)

Adds the backend for sourcing environmental feeds from Central's NATS
JetStream firehose instead of (or alongside) meshai's native adapters.
Architecture is Matt-approved Option 3' (dedicated package + per-adapter
source switch surfaced on the existing Environmental config).

NO-OP POSTURE (intentional): every adapter defaults to feed_source="native"
and environmental.central.enabled defaults false, so on a stock config the
CentralConsumer starts and subscribes to nothing -- behavior is byte-for-byte
v0.3. Live env_feeds.yaml is unchanged on disk; an operator who touches
nothing sees no change. Flipping an adapter to central is Phase C.3; the
dashboard UI for it is Phase C.2.

What landed:
- meshai/central/ package (CentralConsumer): async start()/stop(), JetStream
  durable subscribe to subjects derived from adapters with feed_source=central,
  and _on_message -> normalize -> bus.emit. nats-py is lazy-imported only on
  the connect path, so no-op boot has zero NATS dependency.
- Normalization (CloudEvents envelope -> Central Event -> upstream data):
    source   = inner Event.adapter
    category = Central hierarchical string -> meshai flat, via a small
               table-driven prefix map (map_category)
    severity = 0|1->routine, 2->priority, 3|4->immediate, null->routine
    lat/lon  = geo.centroid, swapped from GeoJSON [lon,lat] -> (lat,lon)
    group_key/inhibit = outer envelope id (dedup parity with native adapters)
    expires/timestamp parsed from ISO-8601
    Event.data = upstream payload verbatim (generic _enriched merge, preserved
                 as-is incl. hydro's extra usgs_site/usgs_stats bundles)
- Tombstone (`.removed.` subject or `:removed` id suffix) -> a "clear" Event
  carrying the ORIGINAL group_key (`:removed` stripped) + data._central_tombstone
  so the grouper/inhibitor lets the prior event lapse naturally.
- config.py: a `_SourcedFeed` mixin adds `feed_source: native|central`
  (validated in __post_init__) to all 10 adapter configs; new
  CentralConsumerConfig as environmental.central { enabled, url, durable,
  connect_timeout }. Both ride the generic _dict_to_dataclass coercion, so
  they are GUI-editable via PUT /config/environmental (Rule 17) -- frontend
  fields come in C.2.
- env/store.py: each adapter is instantiated only when
  enabled AND feed_source=="native"; a feed_source=central adapter is skipped
  natively (debug-logged) so Central can own it without a duplicate.
- main.py: CentralConsumer constructed + started after start_pipeline(),
  stopped in stop().

DEVIATION FROM SPEC (documented): the spec named the new field `source`, but
FIRMSConfig already has a `source` field (the satellite product,
"VIIRS_SNPP_NRT"). To avoid the collision the field is named **feed_source**
across all adapters. Everything else follows the spec.

NETWORKING: zero infra change required. The meshai container already reaches
the Central NATS server directly (TCP to 100.64.0.12:4222 OK) and resolves
central.echo6.mesh via the Phase 2.6.6 MagicDNS fix. No docker-compose edit;
default bridge works (LXC host masquerades to the Tailscale CGNAT range). The
lighter bridge-route / host-net / sidecar fallbacks were not needed.

Tests: tests/test_central_consumer.py (11) + tests/test_config_source_field.py
(6): no-op-when-native, subjects-when-central, source-gate skips native
instantiation, normalize+emit, _enriched preserved verbatim, tombstone->clear,
severity map (0-4/null), category map (>=4 strings), async _on_message
emits+acks, start() no-op without NATS, feed_source default/validate/reject/
dict-coercion. Full suite: 269 passed (was 253 + 16 new).

Verification: (A) no bare self._x() in consumer.py. (B) py_compile clean.
(C) 269 passed. (D) rebuilt prod -- 8 native adapters, pipeline started,
native nifc/traffic emissions still flowing, healthy, no errors, log
"CentralConsumer started; 0 subjects subscribed -- no adapters set to central".
(E) in-container synthetic _on_message injection normalized correctly
(usgs_quake/earthquake_event/immediate, centroid swapped, _enriched preserved)
and reached the bus; ephemeral, no config change to roll back.

C.2 (dashboard frontend for the feed_source switch + central connection) is next.

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

meshai/env/store.py

@@ -29,49 +29,53 @@ class EnvironmentalStore:
         self._region_anchors = region_anchors or []
 
         # Create adapter instances based on config
-        if config.nws.enabled:
+        if config.nws.enabled and config.nws.feed_source == "native":
             from .nws import NWSAlertsAdapter
             self._adapters["nws"] = NWSAlertsAdapter(config.nws)
 
-        if config.swpc.enabled:
+        if config.swpc.enabled and config.swpc.feed_source == "native":
             from .swpc import SWPCAdapter
             self._adapters["swpc"] = SWPCAdapter(config.swpc)
 
-        if config.ducting.enabled:
+        if config.ducting.enabled and config.ducting.feed_source == "native":
             from .ducting import DuctingAdapter
             self._adapters["ducting"] = DuctingAdapter(config.ducting)
 
-        if config.fires.enabled:
+        if config.fires.enabled and config.fires.feed_source == "native":
             from .fires import NICFFiresAdapter
             self._adapters["nifc"] = NICFFiresAdapter(config.fires, self._region_anchors)
 
-        if config.avalanche.enabled:
+        if config.avalanche.enabled and config.avalanche.feed_source == "native":
             from .avalanche import AvalancheAdapter
             self._adapters["avalanche"] = AvalancheAdapter(config.avalanche)
 
-        if config.usgs.enabled:
+        if config.usgs.enabled and config.usgs.feed_source == "native":
             from .usgs import USGSStreamsAdapter
             self._adapters["usgs"] = USGSStreamsAdapter(config.usgs)
 
-        if config.usgs_quake.enabled:
+        if config.usgs_quake.enabled and config.usgs_quake.feed_source == "native":
             from .usgs_quake import USGSQuakeAdapter
             self._adapters["usgs_quake"] = USGSQuakeAdapter(config.usgs_quake)
 
-        if config.traffic.enabled:
+        if config.traffic.enabled and config.traffic.feed_source == "native":
             from .traffic import TomTomTrafficAdapter
             self._adapters["traffic"] = TomTomTrafficAdapter(config.traffic)
 
-        if config.roads511.enabled:
+        if config.roads511.enabled and config.roads511.feed_source == "native":
             from .roads511 import Roads511Adapter
             self._adapters["roads511"] = Roads511Adapter(config.roads511)
 
         # FIRMS needs reference to NIFC adapter for cross-referencing
-        if config.firms.enabled:
+        if config.firms.enabled and config.firms.feed_source == "native":
             from .firms import FIRMSAdapter
             fires_adapter = self._adapters.get("nifc")
             self._firms = FIRMSAdapter(config.firms, self._region_anchors, fires_adapter)
             self._adapters["firms"] = self._firms
 
+        _central = [n for n in ("nws", "swpc", "ducting", "fires", "avalanche", "usgs", "usgs_quake", "traffic", "roads511", "firms")
+                    if getattr(getattr(config, n, None), "feed_source", "native") == "central"]
+        if _central:
+            logger.debug("Adapters sourced from Central (native skipped): %s", _central)
         logger.info(f"EnvironmentalStore initialized with {len(self._adapters)} adapters")
 
     def refresh(self) -> bool: