[GoDiao]

Moves the desktop app from Tauri to Electron, as decided in #174, and removes Tauri. Electron is the only desktop shell; nothing keeps compatibility with files the Tauri shell wrote.

Closes #174
Closes #173

Why

The #172 measurements showed WKWebView on macOS laying out a streaming reply about 20x slower than Chromium (about 20 ms per update, 265 ms at the slow end, against about 1 ms). The spike results are in #174 (comment) and the decisions in #174 (comment).

What changed

• Terminal in the sidecar. src/server/services/terminalService.ts runs the PTY with Bun (openpty on macOS, ConPTY on Windows) and ports the shell resolution, login-shell environment, UTF-8 locale and Bash path check from Rust.
  • It is served over a WebSocket at /terminal, plus GET /api/terminal/default-shell and POST /api/terminal/validate-bash-path.
  • All three accept only local-trusted requests and answer 403 to H5 clients, also when H5 access is on.
  • Closing a terminal sends SIGHUP, because interactive shells ignore SIGTERM.
• Login environment. The sidecar launcher merges the user's login-shell environment itself, which the Rust shell used to do. That is how an app opened from Finder gets the Homebrew PATH. The read is bounded by a 2 s timeout as a whole, so a slow shell rc file cannot hold up startup.
• Electron main process (desktop/electron). It covers:
  • the window, with state stored in Electron's screen coordinates under the user data folder;
  • the macOS menu and the tray, where closing hides to the tray;
  • single instance;
  • notifications, where a click opens the target session;
  • open and save dialogs, and session export;
  • portable mode;
  • the dreamcoder:// protocol with a content security policy.
  • The page reaches the shell only through a preload bridge used by desktop/src/lib/shell.
• Notifications on macOS. Electron cannot read the macOS notification permission, so Settings shows it as managed by system settings, with a button that opens the notification pane.
• Packaging. electron-builder builds a macOS arm64 .dmg and a Windows x64 NSIS installer.
  • release.yml and smoke-test.yml build and check them; Rust is no longer needed.
  • Signing and notarization turn on when the signing secrets are set.
  • There is no auto-updater yet (Ship in-app auto-update with electron-updater #118); a manual check says updates are not configured.
• Removed. desktop/src-tauri, the @tauri-apps/* packages, the Tauri scripts and Vite plugin, useWindowDrag, and the terminal-config.json migration from refactor(desktop): thin the shell and route all shell calls through one module #179.
  • Title areas drag the window through CSS app-region.
• Docs. README (en/zh), desktop README, desktop/electron/README.md, CONTRIBUTING, TROUBLESHOOTING, ROADMAP, WEB_USAGE and AGENTS.md. A CHANGELOG [Unreleased] entry says what upgrading users will see:
  • on Windows, a new install folder;
  • window position, portable mode and webview-stored preferences start fresh.
• Fixed along the way.
  • The memory API answered 500 for a missing memory file, and a chat link to one showed "An unexpected error occurred". It now answers 404, and the page selects the project without an error.
  • The settings close button covered page actions such as Add Provider.

How I tested

• bun test: 1428 pass, 0 fail.
• cd desktop && bun run lint: clean. It now also type-checks desktop/electron.
• bun run test -- --run: 125 files, 1320 passed, 4 skipped.
• The zero-comment grep from AGENTS.md is clean on the added lines.
• The touched server tests pass with --randomize --seed=1.
• New tests were checked to fail without their fix:
  • memory 404;
  • the login-environment timeout;
  • the H5-enabled terminal rejection.
• macOS dev app (bun run electron:dev):
  • The terminal starts in the session cwd. Input, Chinese output, resize, exit code and Restart work, and closing a tab or quitting ends the shell.
  • Single instance, hide to tray and show, session export, the missing-sidecar error page, and cleanup on SIGTERM work.
  • Title bar alignment, the settings close button and the memory page were checked by hand.
• macOS packaged .dmg, built at ddbbdcb, before the last two commits:
  • codesign --verify --deep --strict passes, and the sidecar has allow-jit;
  • /api/status, /api/sessions and the ripgrep search work;
  • the page loads under the CSP without violations;
  • the terminal works over the packaged sidecar.
• The diff was reviewed by GPT reviewers, one per dimension, with Sonnet verifying each finding. The confirmed findings are fixed in 3dc46dd.

Not verified

• Anything on Windows. The installer, the install folder, the ConPTY terminal, toasts, the frameless window buttons and the NSIS hooks have not run outside CI. This PR runs release.yml, which builds both installers.
• Windows terminal tests. The terminal tests skip on Windows, and bun test CI runs on Ubuntu only. The Windows smoke test does not open a terminal yet.
• Real macOS notification delivery and signed or notarized builds.
• Linux.