chore: perform widespread code cleanup and formatting

Perform a comprehensive code cleanup across multiple modules to improve code quality, consistency, and maintainability.

Key changes include:
- Removing numerous unused imports.
- Standardizing import order.
- Eliminating trailing whitespace and inconsistent newlines.
- Updating legacy type hints to modern syntax (e.g., `List` -> `list`).
- Making minor improvements for code robustness and style.

src/chat/chatter_manager.py

@@ -1,6 +1,6 @@
 import asyncio
 import time
-from typing import Any, TYPE_CHECKING
+from typing import TYPE_CHECKING, Any
 
 from src.chat.planner_actions.action_manager import ChatterActionManager
 from src.common.logger import get_logger