Add generic-mode URL validation and UI

Introduce a "generic_mode" option to allow validating/downloading from non-YouTube sites and wire it through the UI, config, and validation logic. Key changes:

- Add generic_mode default to ConfigManager and persist setting from DownloadSettingsDialog (checkbox + help text).
- Extend validate_video_url to accept a generic_mode flag and allow any http/https URL with a domain when enabled; pass this flag from Analysis and Download flows.
- Update YTSageApp to load/save generic_mode, update URL placeholder and settings tooltip behavior, and refresh tooltip when settings change.
- Improve robustness in FormatTableMixin: handle None/incorrect types for format_note, abr, resolution, ext, and codec values to avoid type errors and ensure consistent display.
- Add localization entries for generic mode, placeholder, and related help text across multiple language files and update the in-app default localization strings.

These changes enable broader site support via yt-dlp while hardening UI format handling and keeping user settings persistent.

ytsage/utils/ytsage_config_manager.py

@@ -71,6 +71,7 @@ class ConfigManager:
     _settings: Dict[str, Any] = {}
     _default_config: Dict[str, Any] = {
         "download_path": str(USER_HOME_DIR / "Downloads"),
+        "generic_mode": False,
         "speed_limit_value": None,
         "speed_limit_unit_index": 0,
         "cookie_source": "browser",  # "browser" or "file"