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/plugin_system/base/base_action.py

@@ -742,7 +742,7 @@ class BaseAction(ABC):
         if not case_sensitive:
             search_text = search_text.lower()
 
-        matched_keywords: ClassVar = []
+        matched_keywords  = []
         for keyword in keywords:
             check_keyword = keyword if case_sensitive else keyword.lower()
             if check_keyword in search_text: