fix(km): normalize legacy timestamps

apps/api/src/repositories/knowledge_repository.py

@@ -27,6 +27,7 @@ from src.models.knowledge import (
     KnowledgeEntry,
     KnowledgeEntryCreate,
 )
+from src.utils.timezone import now_taipei
 
 logger = structlog.get_logger(__name__)
 
@@ -199,6 +200,13 @@ def _normalize_tags(value: object) -> list[str]:
     return [str(value).strip()] if str(value).strip() else []
 
 
+def _normalize_int(value: object, *, fallback: int = 0) -> int:
+    try:
+        return int(value or fallback)
+    except (TypeError, ValueError):
+        return fallback
+
+
 def _normalized_category_expr():
     return func.coalesce(
         func.nullif(func.trim(KnowledgeEntryRecord.category), ""),
@@ -612,10 +620,10 @@ class KnowledgeDBRepository:
             # P1-1 M3 2026-04-28 ogt + Claude Sonnet 4.6: 冪等 key
             path_type=get("path_type"),
             symptoms_hash=get("symptoms_hash"),
-            view_count=int(get("view_count") or 0),
+            view_count=_normalize_int(get("view_count")),
             created_by=get("created_by"),
-            created_at=get("created_at"),
-            updated_at=get("updated_at"),
+            created_at=get("created_at") or now_taipei(),
+            updated_at=get("updated_at") or get("created_at") or now_taipei(),
         )
 
 

apps/api/tests/test_knowledge_repository_read_model.py

@@ -86,10 +86,21 @@ def test_knowledge_read_model_normalizes_legacy_tag_shapes_and_null_counts() ->
 
     json_tag_entry = repo._to_model(_record(tags='["telegram", " ai_loop "]', view_count=None))
     scalar_tag_entry = repo._to_model(_record(tags="telegram"))
+    bad_count_entry = repo._to_model(_record(view_count="not-a-number"))
 
     assert json_tag_entry.tags == ["telegram", "ai_loop"]
     assert json_tag_entry.view_count == 0
     assert scalar_tag_entry.tags == ["telegram"]
+    assert bad_count_entry.view_count == 0
+
+
+def test_knowledge_read_model_fills_missing_legacy_timestamps() -> None:
+    repo = KnowledgeDBRepository(db=object())  # type: ignore[arg-type]
+
+    entry = repo._to_model(_record(created_at=None, updated_at=None))
+
+    assert entry.created_at is not None
+    assert entry.updated_at is not None
 
 
 def test_knowledge_read_model_defaults_null_or_blank_category() -> None: