fix(governance): normalize event and dispatch queries

apps/api/src/services/governance_query_service.py

@@ -85,8 +85,38 @@ def _extract_impact(details: dict) -> str:
     return ""
 
 
+def _extract_remediation(details: dict) -> str | None:
+    """
+    將治理事件 details.remediation 正規化為前端可顯示的短字串。
+
+    Production 事件已出現 dict 形態（例如 {"items": [...]}），API response
+    schema 則是字串。這裡做 read-side normalization，避免歷史資料讓
+    /governance events 變成 500。
+    """
+    remediation = details.get("remediation")
+    if remediation is None:
+        return None
+    if isinstance(remediation, str):
+        return remediation[:160]
+    if isinstance(remediation, dict):
+        for key in ("summary", "message", "reason", "action"):
+            value = remediation.get(key)
+            if isinstance(value, str) and value:
+                return value[:160]
+        items = remediation.get("items")
+        if isinstance(items, list):
+            normalized = [str(item) for item in items if item is not None]
+            if normalized:
+                return "；".join(normalized[:3])[:160]
+        return str(remediation)[:160]
+    if isinstance(remediation, list):
+        normalized = [str(item) for item in remediation if item is not None]
+        return "；".join(normalized[:3])[:160] if normalized else None
+    return str(remediation)[:160]
+
+
 def _to_governance_event(row: AiGovernanceEvent) -> GovernanceEvent:
-    details = row.details or {}
+    details = row.details if isinstance(row.details, dict) else {}
     return GovernanceEvent(
         id=row.id,
         event_type=row.event_type,
@@ -96,7 +126,7 @@ def _to_governance_event(row: AiGovernanceEvent) -> GovernanceEvent:
         resolved_at=row.resolved_at,
         impact=_extract_impact(details),
         details=details,
-        remediation=details.get("remediation"),
+        remediation=_extract_remediation(details),
         dispatch_ids=details.get("dispatch_ids", []),
     )
 
@@ -239,14 +269,14 @@ async def _query_dispatch_table(
             d.dispatch_status,
             d.decision_context,
             d.playbook_id,
-            d.created_at,
+            d.dispatched_at AS created_at,
             d.dispatched_at,
             d.completed_at,
-            d.operator_note
+            NULL::text AS operator_note
         FROM governance_remediation_dispatch d
         JOIN ai_governance_events e ON e.id = d.governance_event_id
         WHERE d.dispatch_status = :dispatch_status
-        ORDER BY d.created_at DESC
+        ORDER BY d.dispatched_at DESC
     """)
 
     count_sql = text("""

apps/api/tests/test_ai_governance_endpoints.py

@@ -31,6 +31,11 @@ from src.models.governance import (
     GovernanceSummaryResponse,
     map_severity,
 )
+from src.services.governance_query_service import (
+    _extract_remediation,
+    _query_dispatch_table,
+    _to_governance_event,
+)
 
 TAIPEI = timezone(timedelta(hours=8))
 NOW = datetime(2026, 5, 2, 12, 0, tzinfo=TAIPEI)
@@ -183,6 +188,40 @@ class TestEventsEndpoint:
         assert items[2]["severity"] == "info"
 
 
+class TestEventsReadSideNormalization:
+    def test_remediation_dict_is_normalized_to_string(self):
+        """production details.remediation 可能是 dict，response schema 必須仍回字串."""
+        remediation = _extract_remediation({
+            "remediation": {
+                "items": [
+                    "補齊 ADR-100 SLO emitter",
+                    "設置 PROMETHEUS_MULTIPROC_DIR",
+                ]
+            }
+        })
+
+        assert remediation == "補齊 ADR-100 SLO emitter；設置 PROMETHEUS_MULTIPROC_DIR"
+
+    def test_governance_event_accepts_dict_remediation(self):
+        """dict remediation 不應讓 GovernanceEvent Pydantic validation 變成 500."""
+        row = type("Row", (), {
+            "id": "evt-001",
+            "event_type": "governance_slo_data_gap",
+            "triggered_at": NOW,
+            "resolved": False,
+            "resolved_at": None,
+            "details": {
+                "message": "SLO metrics missing",
+                "remediation": {"items": ["補齊 SLO emitter"]},
+            },
+        })()
+
+        event = _to_governance_event(row)
+
+        assert event.remediation == "補齊 SLO emitter"
+        assert event.impact == "SLO metrics missing"
+
+
 # =============================================================================
 # 3. queue endpoint graceful fallback
 # =============================================================================
@@ -240,6 +279,18 @@ class TestQueueEndpoint:
         r = client.get("/api/v1/ai/governance/queue?dispatch_status=unknown")
         assert r.status_code == 422
 
+    def test_queue_query_uses_production_dispatch_schema(self):
+        """queue 查詢必須對齊 migration schema：使用 dispatched_at，不讀不存在的 created_at/operator_note."""
+        import inspect
+
+        source = inspect.getsource(_query_dispatch_table)
+
+        assert "d.dispatched_at AS created_at" in source
+        assert "ORDER BY d.dispatched_at DESC" in source
+        assert "NULL::text AS operator_note" in source
+        assert "d.created_at" not in source
+        assert "d.operator_note" not in source
+
 
 # =============================================================================
 # 4. summary endpoint compliance_rate