feat: v0.7.0 — chat session hardening, validated atoms, navigation fixes

- Refactored useChatSession into smaller focused hooks
- Added validated-atom pattern for runtime type safety on persistent atoms
- Fixed navigation edge cases (commit envelope, ephemeral resets)
- Hardened flow routing with proper transaction guards
- Removed deprecated useWorkflowReset in favor of inline reset logic
- Added comprehensive test coverage: 13 new test files with fixtures
- Shared test utilities (test-utils.tsx, vitest-setup.ts)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

fix: auto-update restart broken by before-quit telemetry flush

The before-quit handler calls event.preventDefault() to do an async
telemetry flush before quitting. This breaks autoUpdater.quitAndInstall()
because the updater loses control of the quit lifecycle — the installer
never launches after the deferred app.quit().

Fix: skip the async flush when quit is triggered by the updater. The
isQuittingForUpdate() flag lets the before-quit handler return immediately
so autoUpdater can complete its quit-and-install sequence.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

fix(ci): run build:shared before tests in release workflow

The mcp-config test needs mcp-search-proxy/dist/ which only exists
after build:shared. Release workflow was running tests without it.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

fix(ci): decouple electron-builder from GitHub release creation

electron-builder's --publish always creates a draft release and refuses
to upload assets when a non-draft release already exists for the tag.
Switch to --publish never and upload artifacts via softprops/action-gh-release
which handles both new and existing releases.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

chore: bump version to 0.2.0

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: improve splitter decomposition and workflow runner reliability

- Add multi-strategy splitter decomposition (thematic, sequential, structural)
- Harden workflow runner error handling
- Update templates with improved prompts
- Add splitter tests

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

fix: updater, sidebar, execution reset, and batch runner improvements

- Fix auto-updater channel detection for packaged builds
- Refactor project sidebar with improved UX
- Harden execution and workflow reset hooks
- Add batch runner tests
- Minor design system and styling updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>