## 1. Implementation
- [x] 1.1 Add `electron-updater` dependency.
- [x] 1.2 Configure electron-builder generic publishing at the TrueGrowth stable update URL.
- [x] 1.3 Implement Electron update state, events, manual checks, download, and restart-install commands.
- [x] 1.4 Expose a safe preload update bridge to the renderer.
- [x] 1.5 Add Workbench update entry and dialog with light/dark styling.
- [x] 1.6 Add release manifest generation/verification tooling for 1Panel upload.

## 2. Validation
- [x] 2.1 Run Electron main/preload syntax checks.
- [x] 2.2 Run web typecheck for the Workbench UI.
- [x] 2.3 Run the release manifest script with a fixture release directory.
- [ ] 2.4 Validate OpenSpec change if the `openspec` CLI is available. (`openspec` was not found in PATH.)