fix(kg): tighten temporal handling and cleanup

mempalace/config.py

@@ -93,14 +93,16 @@ def sanitize_kg_value(value: str, field_name: str = "value") -> str:
 # Accepted:
 #   YYYY-MM-DD
 #   YYYY-MM-DDTHH:MM:SSZ
+#   YYYY-MM-DDTHH:MM:SS+00:00  (normalized to ...Z)
 #
 # Rejected:
-#   partial dates, naive datetimes, timezone offsets, fractional seconds,
-#   and SQLite-style space-separated datetimes.
+#   partial dates, naive datetimes, non-UTC timezone offsets, fractional
+#   seconds, and SQLite-style space-separated datetimes.
 _ISO_DATE_RE = re.compile(r"^\d{4}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12]\d|3[01])$")
 
 _ISO_UTC_DATETIME_RE = re.compile(
-    r"^\d{4}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12]\d|3[01])" r"T(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\dZ$"
+    r"^\d{4}-(?:0[1-9]|1[0-2])-(?:0[1-9]|[12]\d|3[01])"
+    r"T(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:Z|\+00:00)$"
 )
 
 
@@ -127,6 +129,7 @@ def sanitize_iso_temporal(value, field_name: str = "date"):
 
     - ``YYYY-MM-DD``
     - ``YYYY-MM-DDTHH:MM:SSZ``
+    - ``YYYY-MM-DDTHH:MM:SS+00:00`` normalized to ``...Z``
 
     Partial dates are rejected because KG queries compare TEXT temporal values.
     Non-canonical datetime forms are rejected because mixed temporal string
@@ -148,6 +151,9 @@ def sanitize_iso_temporal(value, field_name: str = "date"):
             "(expected YYYY-MM-DD or YYYY-MM-DDTHH:MM:SSZ)"
         ) from None
 
+    if value.endswith("+00:00"):
+        value = f"{value[:-6]}Z"
+
     return value
 
 

mempalace/knowledge_graph.py

@@ -81,20 +81,6 @@ def _temporal_end_key(value: Optional[str]) -> Optional[str]:
     return value
 
 
-def _triple_valid_at(valid_from: Optional[str], valid_to: Optional[str], as_of: str) -> bool:
-    as_of_key = _temporal_start_key(as_of)
-    valid_from_key = _temporal_start_key(valid_from)
-    valid_to_key = _temporal_end_key(valid_to)
-
-    if valid_from_key is not None and valid_from_key > as_of_key:
-        return False
-
-    if valid_to_key is not None and valid_to_key < as_of_key:
-        return False
-
-    return True
-
-
 def _sql_temporal_start_expr(column: str) -> str:
     """SQLite expression for comparing valid_from-style temporal values."""
 
@@ -230,15 +216,6 @@ class KnowledgeGraph:
         self.close()
         return False
 
-    def __del__(self):
-        """Best-effort cleanup for callers/tests that forget to call close()."""
-        try:
-            self.close()
-        except Exception:
-            # Destructors must never raise, especially during interpreter
-            # shutdown when module globals may already be partially torn down.
-            pass
-
     def _entity_id(self, name: str) -> str:
         return name.lower().replace(" ", "_").replace("'", "")
 

tests/conftest.py

@@ -42,6 +42,16 @@ def _reset_mcp_cache():
         try:
             from mempalace import mcp_server
 
+            for kg in list(getattr(mcp_server, "_kg_by_path", {}).values()):
+                close = getattr(kg, "close", None)
+                if close is not None:
+                    try:
+                        close()
+                    except Exception:
+                        pass
+            if hasattr(mcp_server, "_kg_by_path"):
+                mcp_server._kg_by_path.clear()
+
             mcp_server._client_cache = None
             mcp_server._collection_cache = None
         except (ImportError, AttributeError):

tests/test_config.py

@@ -341,3 +341,7 @@ def test_iso_temporal_rejects_invalid_calendar_date():
 def test_iso_temporal_error_names_field():
     with pytest.raises(ValueError, match="as_of"):
         sanitize_iso_temporal("2026-05-06T14:23", "as_of")
+
+
+def test_iso_temporal_normalizes_plus_zero_offset_to_z():
+    assert sanitize_iso_temporal("2026-05-06T14:23:00+00:00") == "2026-05-06T14:23:00Z"