New MCP tools:
- grant_permission: Grant app permissions (Android runtime / iOS privacy)
- revoke_permission: Revoke app permissions
- reset_permissions: Reset all permissions for an app
- annotate_screenshot: Screenshot with colored bounding boxes and numbered element labels

Infrastructure:
- Add vitest test framework with 73 unit tests
- Tests for ui-parser (parseUiHierarchy, findBestMatch, analyzeScreen, etc.)
- Tests for image utils (compressScreenshot, annotateScreenshot)
- Fix MCP response handler to return both image and text content

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>