Finish CUST-WP-0011 and implement STATE-WP-0061 suggestion backlog.

Add persisted Suggestion entities with WSJF ranking, relevance bumps,
REST/MCP write surfaces, /suggestions dashboard page, and daily triage
digest integration. Document the cluster operating model, archive the
completed migration workplan, and seed WARDEN-WP-0012 routing scenarios.

api/models/__init__.py

@@ -34,6 +34,12 @@ from api.models.workplan_launch_request import WorkplanLaunchRequest
 from api.models.fabric_graph import FabricGraphImport, FabricGraphNode, FabricGraphEdge
 from api.models.legacy_meter import LegacyInterface, LegacyInterfaceUsageBucket
 from api.models.write_idempotency_key import WriteIdempotencyKey
+from api.models.suggestion import (
+    Suggestion,
+    SuggestionNote,
+    SuggestionRelevanceBump,
+    SuggestionStage,
+)
 
 __all__ = [
     "Base",
@@ -67,4 +73,5 @@ __all__ = [
     "FabricGraphImport", "FabricGraphNode", "FabricGraphEdge",
     "LegacyInterface", "LegacyInterfaceUsageBucket",
     "WriteIdempotencyKey",
+    "Suggestion", "SuggestionNote", "SuggestionRelevanceBump", "SuggestionStage",
 ]