fix(automation): enforce durable alert closure

Restore D037 durable incident readback without weakening database failure semantics.

Fence Agent99 dispatch and terminal learning to canonical identities, durable leases, verifier receipts, and reconciler-owned checkpoints.

Drain backup and restore legacy receipts in bounded cohorts with strict transport, claim, projection, and no-false-green controls.

Keep SSH service refusal visible while separating it from broker network-policy reachability.

apps/api/src/services/incident_engine.py

@@ -25,7 +25,7 @@ from typing import Any, Protocol, runtime_checkable
 import structlog
 
 from src.core.redis_client import get_redis
-from src.models.incident import Incident
+from src.models.incident import Incident, parse_signal_source
 from src.services.graph_rag import BlastRadiusResult, topology_graph
 from src.services.incident_memory import get_incident_memory
 from src.utils.incident_converter import brain_to_local
@@ -215,7 +215,11 @@ class IncidentEngineAdapter:
 
     async def process_signal(self, signal_data: dict[str, Any]) -> Incident | None:
         """處理 Signal，返回 LocalIncident (brain 輸出轉換)"""
-        brain_incident = await self._engine.process_signal(signal_data)
+        normalized_signal = dict(signal_data)
+        normalized_signal["source"] = parse_signal_source(
+            normalized_signal.get("source")
+        )
+        brain_incident = await self._engine.process_signal(normalized_signal)
         if brain_incident is None:
             return None
         return brain_to_local(brain_incident)