3.2.1 a mix of user-facing improvements, broader parsing support, localization coverage, and project-maintenance updates.

[doctorlai-msrc]

Description

This PR prepares the extension for the 3.2.1 release with a mix of user-facing improvements, broader parsing support, localization coverage, and project-maintenance updates.

User-facing changes

• Adds broader direct media detection for video, audio, and image URLs.
• Adds one-click copy/download actions, bulk copy/download actions, media-type tags, and result counts in the popup.
• Adds dark mode support for the popup UI.
• Adds a keyboard shortcut command (Alt+Shift+V) to open the extension popup.
• Adds safer handling for restricted pages so the popup does not try to scan browser-internal pages or Chrome Web Store pages.
• Adds service-worker-only toolbar badge/context-menu behavior.

Parser and helper changes

• Adds shared media extension/type helpers in functions.js.
• Improves filename suggestions by preserving known media extensions found in paths or query parameters.
• Adds a broad last-resort parser for direct media links embedded in page HTML.
• Adds additional parser/test coverage for media URLs, filename inference, restricted URLs, and branch cases.

Localization

• Adds popup UI translations for additional languages.
• Adds matching Chrome _locales metadata for newly supported locales.
• Adds i18n tests to ensure language files, main.html, and translate.js stay wired together.

Project / release maintenance

• Adds community docs: CONTRIBUTING.md, SECURITY.md, PRIVACY.md, and a pull request template.
• Adds Dependabot configuration for npm dependencies and GitHub Actions.
• Updates README badges and developer documentation.
• Adds/documented npm run package for creating the Chrome Web Store zip package.
• Updates package and manifest versions to 3.2.1.

How Has This Been Tested?

• npm run check passes locally.
• cd video-url-parser && npm test -- --grep "isRestrictedUrl|media type|inferMediaExtension|extract_all_media_urls|i18n" passes (158 passing).
• Broad test run completed successfully (308 passing).
• git diff --check 556f732...HEAD && git diff --check passes.
• npm run package successfully creates simple-video-download-helper-3.2.1.zip at the repository root.
• VS Code diagnostics showed no errors in the touched runtime/test files reviewed.

Notes

• npm run build only creates video-url-parser/dist/dist.min.js; use npm run package to build the release zip.
• dist/dist.min.js is generated and should not be committed.