feat: deliverable review gate, app lifecycle fixes, CI/CD pipeline

- Add deliverable review gate: pause workflow when agents produce important
  documents (PRDs, design docs, etc.) for human review before continuing
- Add company-level reviewDeliverables setting with onboarding card selector
- Block agent heartbeats when deliverable review is pending (agent + CEO)
- Trigger review at document creation time in API server for reliability
- Fix autoApproveHires vs reviewDeliverables conflict in approval-policy
- Fix app quit: force-exit on all platforms (macOS Dock, Windows tray, Linux)
- Add multi-platform CI/CD pipeline (macOS arm64/x64, Windows x64/arm64,
  Linux x64/arm64 with deb/AppImage/rpm/snap) with code signing support

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

.gitignore

@@ -14,6 +14,15 @@ win-unpacked
 test-results/
 playwright-report/
 
+# Signing certificates (NEVER commit these)
+*.p12
+*.cer
+*.pem
+*.key
+*.p8
+*.provisionprofile
+*.mobileprovision
+
 # Environment files
 .env
 .env.local