fix(app): share synced session data

[Brendonovich]

Summary

• load notification sessions through the directory sync context
• reuse synchronized session data when restoring project navigation
• keep direct API access only where directory sync is unavailable or being initialized

Testing

• bun typecheck in packages/app
• bun test --only-failures --preload ./happydom.ts ./src/context/layout.test.ts ./src/context/layout-scroll.test.ts ./src/utils/notification-click.test.ts
• repository-wide bun turbo typecheck push hook
• bunx playwright test --config e2e/performance/playwright.config.ts e2e/performance/timeline/first-navigation-benchmark.spec.ts attempted before and after; both runs failed before metrics because the existing smoke fixture did not render the expected Uncommitted changes inquiry session title