Backend:
- Add version field to InstallLibraryRequest
- Add fallback and requested_version to InstallResponse
- Add DELETE /api/libraries/uninstall endpoint
- Enhance install_library() for versioned installs (LibName@version)
- Add semver validation and fallback logic
- Add uninstall_library() method
- Fix _parse_version() to reject non-numeric version parts
Frontend:
- Update installLibrary() with optional version parameter
- Add uninstallLibrary() and resolveLibraryVersion() helpers
- Add version selector dropdown in Library Manager
- Add UNINSTALL button for installed libraries
- Show fallback messages when requested version unavailable
- Add parseLibSpec() and version badges in InstallLibrariesModal