Add drag & drop script variants and enhanced debugging tools

- Introduced multiple JavaScript scripts for handling drag & drop functionality:
  - `bridge_script.js`: Original implementation with popup prevention.
  - `bridge_script_debug.js`: Debug version with extensive logging for troubleshooting.
  - `bridge_script_v2.js`: Enhanced version extending DataTransfer for better integration.
  - `bridge_script_hybrid.js`: Hybrid approach allowing parallel native file drag.
  - `bridge_script_drop_intercept.js`: Intercepts drop events for custom handling.
  - `bridge_script_intercept.js`: Prevents browser drag for ALT+drag, using Qt for file drag.

- Added detailed documentation in `SCRIPT_VARIANTS.md` outlining usage, status, and recommended workflows for each script.
- Implemented logging features to capture drag events, DataTransfer modifications, and network requests for better debugging.
- Enhanced DataTransfer handling to support Windows-specific file formats and improve user experience during drag & drop operations.

src/webdrop_bridge/ui/restricted_web_view.py

@@ -155,7 +155,8 @@ class RestrictedWebEngineView(QWebEngineView):
 
         # Create persistent profile with custom storage location
         # Using "WebDropBridge" as the profile name
-        profile = QWebEngineProfile("WebDropBridge", self)
+        # Note: No parent specified so we control the lifecycle
+        profile = QWebEngineProfile("WebDropBridge")
         profile.setPersistentStoragePath(str(profile_path))
 
         # Configure persistent cookies (critical for authentication)