fix(governance): fail soft work-items readbacks

apps/api/src/api/v1/ai_governance.py

@@ -65,6 +65,7 @@ from src.services.governance_query_service import (
     query_km_review_draft_dedupe,
     query_km_stale_candidates,
 )
+from src.utils.timezone import now_taipei
 
 logger = structlog.get_logger(__name__)
 
@@ -164,12 +165,29 @@ async def get_governance_queue(
         page=page,
         size=size,
     )
-    return await query_governance_queue(
-        dispatch_status=dispatch_status,
-        event_types=event_type,
-        page=page,
-        size=size,
-    )
+    try:
+        return await query_governance_queue(
+            dispatch_status=dispatch_status,
+            event_types=event_type,
+            page=page,
+            size=size,
+        )
+    except Exception as exc:
+        logger.warning(
+            "governance_queue_readback_degraded",
+            dispatch_status=dispatch_status,
+            event_type=event_type,
+            page=page,
+            size=size,
+            error_type=type(exc).__name__,
+        )
+        return GovernanceQueueResponse(
+            items=[],
+            total=0,
+            page=page,
+            size=size,
+            table_pending=True,
+        )
 
 
 # =============================================================================
@@ -190,7 +208,21 @@ async def get_km_review_draft_dedupe(
     owner_action，不自動 archive、不自動 approve/publish KM。
     """
     logger.debug("km_review_draft_dedupe_request", limit=limit)
-    return await query_km_review_draft_dedupe(limit=limit)
+    try:
+        return await query_km_review_draft_dedupe(limit=limit)
+    except Exception as exc:
+        logger.warning(
+            "km_review_draft_dedupe_readback_degraded",
+            limit=limit,
+            error_type=type(exc).__name__,
+        )
+        return KnowledgeReviewDraftDedupeResponse(
+            total_review_drafts=0,
+            event_group_total=0,
+            duplicate_draft_total=0,
+            groups=[],
+            generated_at=now_taipei(),
+        )
 
 
 # =============================================================================