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/plugins/llm_analysis/scheduler.py

@@ -1,6 +1,8 @@
-# #region backend/src/plugins/llm_analysis/scheduler.py [C:3] [TYPE Module] [SEMANTICS scheduler, task, automation]
+# [DEF:backend/src/plugins/llm_analysis/scheduler.py:Module]
+# @COMPLEXITY: 3
+# @SEMANTICS: scheduler, task, automation
 # @BRIEF Provides helper functions to schedule LLM-based validation tasks.
-# @LAYER Domain
+# @LAYER: Domain
 # @RELATION DEPENDS_ON -> [SchedulerService]
 
 from typing import Dict, Any
@@ -9,9 +11,6 @@ from ...core.logger import belief_scope, logger
 
 # #region schedule_dashboard_validation [TYPE Function]
 # @BRIEF Schedules a recurring dashboard validation task.
-# @PARAM: dashboard_id (str) - ID of the dashboard to validate.
-# @PARAM: cron_expression (str) - Standard cron expression for scheduling.
-# @PARAM: params (Dict[str, Any]) - Task parameters (environment_id, provider_id).
 # @SIDE_EFFECT: Adds a job to the scheduler service.
 def schedule_dashboard_validation(dashboard_id: str, cron_expression: str, params: Dict[str, Any]):
     with belief_scope("schedule_dashboard_validation", f"dashboard_id={dashboard_id}"):
@@ -41,8 +40,6 @@ def schedule_dashboard_validation(dashboard_id: str, cron_expression: str, param
 
 # #region _parse_cron [TYPE Function]
 # @BRIEF Basic cron parser placeholder.
-# @PARAM: cron (str) - Cron expression.
-# @RETURN: Dict[str, str] - Parsed cron parts.
 def _parse_cron(cron: str) -> Dict[str, str]:
     # Basic cron parser placeholder
     parts = cron.split()
@@ -57,4 +54,4 @@ def _parse_cron(cron: str) -> Dict[str, str]:
     }
 # #endregion _parse_cron
 
-# #endregion backend/src/plugins/llm_analysis/scheduler.py
+# [/DEF:backend/src/plugins/llm_analysis/scheduler.py:Module]