feat(2-B): add NIFC WFIGS adapters for incidents and perimeters

Two new adapters for wildfire data from NIFC WFIGS:
- wfigs_incidents: Active fire incident locations
- wfigs_perimeters: Active fire perimeter polygons

Features:
- IRWIN GUID dedup via is_published/mark_published
- Fall-off detection with removal events when fires exit current
- Bbox post-filtering with shapely polygon intersection
- Severity mapping from DailyAcres (0-4 scale)
- Subject hierarchy: central.fire.<layer>.<state>.<county>

Ships disabled by default; operators enable via GUI.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

sql/migrations/016_add_wfigs_adapters.sql

@@ -0,0 +1,37 @@
+-- Migration: 016_add_wfigs_adapters
+-- Add WFIGS incident and perimeter adapters to config.adapters
+-- Idempotent: uses ON CONFLICT DO NOTHING
+
+-- WFIGS Incidents adapter
+INSERT INTO config.adapters (name, enabled, cadence_s, settings)
+VALUES (
+    'wfigs_incidents',
+    false,  -- Ships disabled; operator enables via GUI
+    300,
+    jsonb_build_object(
+        'region', jsonb_build_object(
+            'north', 49.0,
+            'south', 31.0,
+            'east', -102.0,
+            'west', -124.0
+        )
+    )
+)
+ON CONFLICT (name) DO NOTHING;
+
+-- WFIGS Perimeters adapter
+INSERT INTO config.adapters (name, enabled, cadence_s, settings)
+VALUES (
+    'wfigs_perimeters',
+    false,  -- Ships disabled; operator enables via GUI
+    300,
+    jsonb_build_object(
+        'region', jsonb_build_object(
+            'north', 49.0,
+            'south', 31.0,
+            'east', -102.0,
+            'west', -124.0
+        )
+    )
+)
+ON CONFLICT (name) DO NOTHING;