Introduce the Electron desktop shell alongside the existing React renderer and local Bun server boundary. The migration keeps the DesktopHost contract explicit across Tauri, Electron, and browser runtimes while adding Electron main/preload services for dialogs, shell, notifications, updates, tray/window lifecycle, terminal, preview WebContentsView, app mode, and release/package validation.
The commit also carries the latest local main desktop command updates, including agent slash entries and hidden-by-default markdown thinking details, so the packaged Electron build matches the current main UX surface.
Constraint: React renderer, local Bun server, REST/WebSocket, and sidecar boundaries must remain reusable during the migration
Constraint: macOS dev packages are ad-hoc signed and cannot prove Developer ID notarization or Gatekeeper release launch
Rejected: Browser-only smoke validation | it cannot exercise native dialogs, keychain prompts, notification behavior, or packaged app startup
Confidence: medium
Scope-risk: broad
Directive: Do not remove Tauri host support until signed Electron release artifacts pass native OS smoke on macOS, Windows, and Linux
Tested: bun run check:desktop
Tested: cd desktop && bun run check:electron
Tested: CSC_IDENTITY_AUTO_DISCOVERY=false bun run electron📦dir
Tested: bun run test:package-smoke --platform macos --package-kind dir --artifacts-dir desktop/build-artifacts/electron
Tested: Computer Use read packaged Electron app window at desktop/build-artifacts/electron/mac-arm64/Claude Code Haha.app
Not-tested: Developer ID signed/notarized Gatekeeper launch
Not-tested: Real OS notification click-to-session action
Not-tested: Windows and Linux packaged app smoke on real hosts
PR #428 added a General Settings zoom slider after the desktop shortcut work already introduced a native-first app zoom controller. Keeping both paths would create double scaling and stale UI state, so the slider now routes through the existing controller and store state while the app shell no longer applies a second CSS zoom.
Constraint: UI zoom is device-local display state and should not be written into shared user settings.
Rejected: Keep cc-haha-ui-zoom plus AppShell style.zoom | it conflicts with shortcut zoom and multiplies visual scale.
Rejected: Persist zoom through /api/settings/user | it would sync display-specific state across machines.
Confidence: high
Scope-risk: moderate
Directive: Keep app zoom behind desktop/src/lib/appZoom.ts; do not add another storage key or DOM zoom application point without migration and shortcut sync tests.
Tested: cd desktop && bun run test -- --run src/lib/appZoom.test.ts src/hooks/useKeyboardShortcuts.test.tsx src/stores/settingsStore.test.ts src/__tests__/generalSettings.test.tsx src/lib/persistenceMigrations.test.ts src/lib/doctorRepair.test.ts
Tested: bun run check:desktop
Not-tested: Real Windows/Linux desktop runtime smoke.
The desktop shell needed predictable zoom controls across macOS,
Windows, and Linux without depending on browser defaults. This adds a
small app zoom controller that persists a bounded zoom factor, maps the
IDE-style primary-modifier shortcuts, and uses native Tauri webview zoom
when available with a browser fallback for H5/dev runs.
Constraint: Issue #407 requested IDE-style zoom shortcuts across macOS, Windows, and Linux
Rejected: Enable Tauri built-in zoom hotkeys only | it would not cover browser/H5 fallback or app-owned persistence consistently
Confidence: high
Scope-risk: narrow
Directive: Keep app zoom bounded and validated before applying persisted localStorage values
Tested: bun run verify; browser smoke on http://127.0.0.1:45679/ with Meta+= and Meta+0
Not-tested: Manual Windows/Linux desktop runtime smoke