feat(logging): implement configurable belief state logging

- Add LoggingConfig model and logging field to GlobalSettings
- Implement belief_scope context manager for structured logging
- Add configure_logger for dynamic level and file rotation settings
- Add logging configuration UI to Settings page
- Update ConfigManager to apply logging settings on initialization and updates

backend/src/core/logger.py

@@ -4,12 +4,32 @@
 # @LAYER: Core
 # @RELATION: Used by the main application and other modules to log events. The WebSocketLogHandler is used by the WebSocket endpoint in app.py.
 import logging
+import threading
 from datetime import datetime
 from typing import Dict, Any, List, Optional
 from collections import deque
+from contextlib import contextmanager
+from logging.handlers import RotatingFileHandler
 
 from pydantic import BaseModel, Field
 
+# Thread-local storage for belief state
+_belief_state = threading.local()
+
+# Global flag for belief state logging
+_enable_belief_state = True
+
+# [DEF:BeliefFormatter:Class]
+# @PURPOSE: Custom logging formatter that adds belief state prefixes to log messages.
+class BeliefFormatter(logging.Formatter):
+    def format(self, record):
+        msg = super().format(record)
+        anchor_id = getattr(_belief_state, 'anchor_id', None)
+        if anchor_id:
+            msg = f"[{anchor_id}][Action] {msg}"
+        return msg
+# [/DEF:BeliefFormatter]
+
 # Re-using LogEntry from task_manager for consistency
 # [DEF:LogEntry:Class]
 # @SEMANTICS: log, entry, record, pydantic
@@ -22,6 +42,81 @@ class LogEntry(BaseModel):
 
 # [/DEF]
 
+# [DEF:BeliefScope:Function]
+# @PURPOSE: Context manager for structured Belief State logging.
+@contextmanager
+def belief_scope(anchor_id: str, message: str = ""):
+    # Log Entry if enabled
+    if _enable_belief_state:
+        entry_msg = f"[{anchor_id}][Entry]"
+        if message:
+            entry_msg += f" {message}"
+        logger.info(entry_msg)
+
+    # Set thread-local anchor_id
+    old_anchor = getattr(_belief_state, 'anchor_id', None)
+    _belief_state.anchor_id = anchor_id
+
+    try:
+        yield
+        # Log Coherence OK and Exit
+        logger.info(f"[{anchor_id}][Coherence:OK]")
+        if _enable_belief_state:
+            logger.info(f"[{anchor_id}][Exit]")
+    except Exception as e:
+        # Log Coherence Failed
+        logger.info(f"[{anchor_id}][Coherence:Failed] {str(e)}")
+        raise
+    finally:
+        # Restore old anchor
+        _belief_state.anchor_id = old_anchor
+
+# [/DEF:BeliefScope]
+
+# [DEF:ConfigureLogger:Function]
+# @PURPOSE: Configures the logger with the provided logging settings.
+# @PRE: config is a valid LoggingConfig instance.
+# @POST: Logger level, handlers, and belief state flag are updated.
+# @PARAM: config (LoggingConfig) - The logging configuration.
+def configure_logger(config):
+    global _enable_belief_state
+    _enable_belief_state = config.enable_belief_state
+
+    # Set logger level
+    level = getattr(logging, config.level.upper(), logging.INFO)
+    logger.setLevel(level)
+
+    # Remove existing file handlers
+    handlers_to_remove = [h for h in logger.handlers if isinstance(h, RotatingFileHandler)]
+    for h in handlers_to_remove:
+        logger.removeHandler(h)
+        h.close()
+
+    # Add file handler if file_path is set
+    if config.file_path:
+        import os
+        from pathlib import Path
+        log_file = Path(config.file_path)
+        log_file.parent.mkdir(parents=True, exist_ok=True)
+        
+        file_handler = RotatingFileHandler(
+            config.file_path,
+            maxBytes=config.max_bytes,
+            backupCount=config.backup_count
+        )
+        file_handler.setFormatter(BeliefFormatter(
+            '[%(asctime)s][%(levelname)s][%(name)s] %(message)s'
+        ))
+        logger.addHandler(file_handler)
+
+    # Update existing handlers' formatters to BeliefFormatter
+    for handler in logger.handlers:
+        if not isinstance(handler, RotatingFileHandler):
+            handler.setFormatter(BeliefFormatter(
+                '[%(asctime)s][%(levelname)s][%(name)s] %(message)s'
+            ))
+# [/DEF:ConfigureLogger]
+
 # [DEF:WebSocketLogHandler:Class]
 # @SEMANTICS: logging, handler, websocket, buffer
 # @PURPOSE: A custom logging handler that captures log records into a buffer. It is designed to be extended for real-time log streaming over WebSockets.
@@ -72,7 +167,7 @@ logger = logging.getLogger("superset_tools_app")
 logger.setLevel(logging.INFO)
 
 # Create a formatter
-formatter = logging.Formatter(
+formatter = BeliefFormatter(
     '[%(asctime)s][%(levelname)s][%(name)s] %(message)s'
 )