Removed external update helper scripts for Linux, macOS, and Windows, and embedded their contents directly into UpdateService.cs. The service now generates the appropriate helper script at runtime, simplifying deployment and reducing reliance on external script files.

Enhanced the macOS update helper script for better reliability, logging, and error handling, including backup and restore logic, .app bundle detection, and log file output. Updated UpdateManager.swift to use a shared Logger, improved shutdown sequence after update, and added more robust error reporting. These changes aim to make the update process safer and easier to debug.

The InstallAppUpdate RPC in the backend is now deprecated and always returns a failure, instructing the client to handle installation locally. The update installation logic and helper scripts have been removed from the backend and reimplemented in the macOS frontend, which now prepares and executes the update process directly. This change improves update reliability and aligns with the new update flow.

Redesigned the SettingsView for improved organization, grouping general, updates, library, and plugins sections with reusable components. Added a toggle for automatic update checks in both SettingsView and UpdateView, defaulting to enabled. Updated the app to only check for updates on launch if the setting is enabled. Bumped the marketing version to 1.3.