deploy: Tauri Desktop App

[ElBeh]

Description

Package SongLab as a native desktop application using Tauri. The Band Sync
server (Express + socket.io) is bundled as a sidecar process, so the full
feature set works out of the box – no terminal, no npm, no dev setup.
Download → Install → Done.

Requirements

• Tauri project setup wrapping the existing Vite/React frontend
• Band Sync server bundled as Tauri sidecar (Node.js or compiled binary)
• Installers for Linux (.deb, .AppImage), Windows (.msi), macOS (.dmg)
• Auto-start Band Sync server from within the app (toggle on/off)
• App icon and metadata (name, version, description)
• GitHub Releases with downloadable installers
• Code signing (optional, nice-to-have for macOS/Windows trust)

Decisions

• Tauri over Electron: significantly smaller bundle size, lower resource usage
• Server bundling strategy TBD: either ship a Node.js runtime as sidecar or rewrite the lightweight server in Rust (native to Tauri)