Refactor configuration management and remove deprecated files

- Consolidated database, file source, and field mapping configurations into dedicated modules under the `config` directory.
- Removed hardcoded database connection details from `migration.py` and replaced them with imports from the new configuration structure.
- Updated `ntfy_utils.py` and `run_incremental_sync.py` to utilize the new configuration imports for cleaner code and better maintainability.
- Deleted `update_config.py` as its contents have been integrated into the new configuration files.
- Added a new `settings.local.json` for managing permissions related to script execution.
- Enhanced the structure of the migration tasks and Excel configurations for better organization and clarity.

db_utils.py

@@ -1,21 +1,20 @@
 # db_utils.py
 import pyodbc
-import config
+from config import SQL_SERVER_CONN, ACCESS_DRIVER
 
 def get_sql_conn():
     """获取 SQL Server 连接"""
-    c = config.SQL_SERVER_CONN
     # 显式添加 TrustServerCertificate=yes 以兼容 ODBC Driver 18+
     conn_str = (
-        f"DRIVER={c['driver']};SERVER={c['server']};"
-        f"DATABASE={c['database']};UID={c['uid']};PWD={c['pwd']};"
-        "Encrypt=yes;TrustServerCertificate=yes;" 
+        f"DRIVER={SQL_SERVER_CONN['driver']};SERVER={SQL_SERVER_CONN['server']};"
+        f"DATABASE={SQL_SERVER_CONN['database']};UID={SQL_SERVER_CONN['uid']};PWD={SQL_SERVER_CONN['pwd']};"
+        "Encrypt=yes;TrustServerCertificate=yes;"
     )
     return pyodbc.connect(conn_str)
 
 def get_access_conn(file_path):
     """获取 Access 连接"""
-    conn_str = f"DRIVER={config.ACCESS_DRIVER};DBQ={file_path};"
+    conn_str = f"DRIVER={ACCESS_DRIVER};DBQ={file_path};"
     return pyodbc.connect(conn_str)
 
 def fmt_table(schema, table):