semantics: complete DEF-to-region migration, fix regressions

- Convert legacy [DEF🆔Type] anchors to #region/#endregion across 329 files
- Reinstate _normalize_timestamp_value in sql_generator.py
- Fix MarkerLogger→logger migration in events.py (molecular CoT markers)
- Fix dataset_review orchestrator dependencies (_build_execution_snapshot)
- Fix config_manager stale-record deletion (moved to save path only)
- Add 77 missing [/DEF:] closers in 5 unbalanced test files
- Update assistant_chat.integration.test.js for #region format
- Apply molecular-cot-logging markers (REASON/REFLECT/EXPLORE) via logger.* methods

backend/src/core/migration/archive_parser.py

@@ -1,8 +1,8 @@
 # #region MigrationArchiveParserModule [C:3] [TYPE Module] [SEMANTICS migration, zip, parser, yaml, metadata]
 # @BRIEF Parse Superset export ZIP archives into normalized object catalogs for diffing.
-# @LAYER Core
-# @INVARIANT Parsing is read-only and never mutates archive files.
+# @LAYER: Core
 # @RELATION DEPENDS_ON -> [LoggerModule]
+# @INVARIANT: Parsing is read-only and never mutates archive files.
 
 import json
 import tempfile
@@ -21,12 +21,12 @@ from ..logger import logger, belief_scope
 # @RELATION CONTAINS -> [_collect_yaml_objects]
 # @RELATION CONTAINS -> [_normalize_object_payload]
 class MigrationArchiveParser:
-    # #region extract_objects_from_zip [TYPE Function]
-    # @BRIEF Extract object catalogs from Superset archive.
-    # @PRE zip_path points to a valid readable ZIP.
-    # @POST Returns object lists grouped by resource type.
-    # @RETURN Dict[str, List[Dict[str, Any]]]
-    # @RELATION DEPENDS_ON -> [_collect_yaml_objects]
+    # [DEF:extract_objects_from_zip:Function]
+    # @PURPOSE: Extract object catalogs from Superset archive.
+    # @RELATION: DEPENDS_ON -> [_collect_yaml_objects]
+    # @PRE: zip_path points to a valid readable ZIP.
+    # @POST: Returns object lists grouped by resource type.
+    # @RETURN: Dict[str, List[Dict[str, Any]]]
     def extract_objects_from_zip(
         self, zip_path: str
     ) -> Dict[str, List[Dict[str, Any]]]:
@@ -49,13 +49,13 @@ class MigrationArchiveParser:
 
             return result
 
-    # #endregion extract_objects_from_zip
+    # [/DEF:extract_objects_from_zip:Function]
 
-    # #region _collect_yaml_objects [TYPE Function]
-    # @BRIEF Read and normalize YAML manifests for one object type.
-    # @PRE object_type is one of dashboards/charts/datasets.
-    # @POST Returns only valid normalized objects.
-    # @RELATION DEPENDS_ON -> [_normalize_object_payload]
+    # [DEF:_collect_yaml_objects:Function]
+    # @PURPOSE: Read and normalize YAML manifests for one object type.
+    # @RELATION: DEPENDS_ON -> [_normalize_object_payload]
+    # @PRE: object_type is one of dashboards/charts/datasets.
+    # @POST: Returns only valid normalized objects.
     def _collect_yaml_objects(
         self, root_dir: Path, object_type: str
     ) -> List[Dict[str, Any]]:
@@ -79,12 +79,12 @@ class MigrationArchiveParser:
                     )
             return objects
 
-    # #endregion _collect_yaml_objects
+    # [/DEF:_collect_yaml_objects:Function]
 
-    # #region _normalize_object_payload [TYPE Function]
-    # @BRIEF Convert raw YAML payload to stable diff signature shape.
-    # @PRE payload is parsed YAML mapping.
-    # @POST Returns normalized descriptor with `uuid`, `title`, and `signature`.
+    # [DEF:_normalize_object_payload:Function]
+    # @PURPOSE: Convert raw YAML payload to stable diff signature shape.
+    # @PRE: payload is parsed YAML mapping.
+    # @POST: Returns normalized descriptor with `uuid`, `title`, and `signature`.
     def _normalize_object_payload(
         self, payload: Dict[str, Any], object_type: str
     ) -> Optional[Dict[str, Any]]:
@@ -149,7 +149,7 @@ class MigrationArchiveParser:
 
             return None
 
-    # #endregion _normalize_object_payload
+    # [/DEF:_normalize_object_payload:Function]
 
 
 # #endregion MigrationArchiveParser