feat(wzdx): WZDx adapter + CENTRAL_TRAFFIC family bootstrap (v0.9.0)

Opens Phase 4 transportation aggregation (Design B, Central-direct). New
registry-driven wzdx adapter polls the FHWA WZDx Feed Registry, fetches each
eligible v4.x GeoJSON feed concurrently, and emits work_zone events into the new
CENTRAL_TRAFFIC stream. Production code; central-supervisor AND central-gui
restart (new adapter class + stream + ADAPTER_GROUPS). Ships disabled.

First adapter to use the category/subject split: category="work_zone.wzdx" (GUI
event_type "work_zone" via split_part) while the NATS subject is
central.traffic.work_zone.{state}. Subject state from the registry row, geocoder
state as fallback. Severity from vehicle_impact (all-lanes-closed=3,
some-lanes-closed=2, all-lanes-open=1, unknown/missing=1). Feed filter
geojson + active + needapikey=false + version 4.x (21 of 39 feeds). 600s cadence.
Dedup composite <data_source_id>:<feature_id> in the shared cursors.db; stateless
discovery (no conftest isolation entry). enrichment_locations uses the canonical
("latitude","longitude") paths.

Full suite: 739 passed, 1 skipped (central and unprivileged zvx, 3x each).

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

tests/test_events_feed_frontend.py

@@ -1142,6 +1142,7 @@ _SAMPLE_INNER = {
     "usgs_quake": {"magnitude": 1.009682538298, "place": "17 km W of Searles Valley, CA"},
     "wfigs_incidents": {"county": "Montezuma", "state": "CO"},
     "wfigs_perimeters": {"county": "Carbon", "state": "MT"},
+    "wzdx": {"road_names": ["I-80"], "direction": "eastbound"},
 }
 
 # Exact expected subjects for the deterministic adapters. swpc_alerts is omitted
@@ -1160,6 +1161,7 @@ _EXPECTED_SUBJECT = {
     "usgs_quake": "Magnitude 1.0 — 17 km W of Searles Valley, CA",
     "wfigs_incidents": "Wildfire incident — Montezuma, CO",
     "wfigs_perimeters": "Wildfire perimeter — Carbon, MT",
+    "wzdx": "Work zone on I-80 eastbound",
 }