feat(t103): cross-device pin and history sync with new tab omnibox

[duongdev]

Summary

Pins and browsing history now sync across devices via the web server, and the New Tab modal becomes an omnibox. See ADR-0017.

• Pin sync — the web server is the source of truth (web/PWA devices already share it). Electron opts in with a per-device Sync setting (toggle + a plaintext tailnet server URL): pin CRUD then rides the shared backend via syncOrLocal, falling back to the local store on any network failure. First enable is server-wins (Electron re-loads the server's pins).
• Browsing history — CDP exposes no History API, so core/history-store.js records it by diffing the existing /json tab poll (page targets only) into frecency-ranked visits, persisted server-side (web-history.json) and served at /api/history.
• New Tab omnibox — new-tab-dialog.tsx now suggests history (matched on URL and title, diacritic-safe) plus a "Switch to tab" action for tabs already open (CDP + local), keeping the pinned quick-launch row for the empty state.
• Tab-item polish — two-line tab titles now fall back to a muted URL on the second line, vertically-centered favicon, bigger centered close button, and a title+URL tooltip on the right.

Testing

• New pure-logic tests (TDD): core/history-store.test.ts + src/lib/tab-suggest.test.ts (25 tests).
• pnpm typecheck, pnpm test (1049), pnpm test:e2e (49) green; biome clean on changed files.
• Verified the omnibox + switch-to-tab and the tab-item polish against a live remote browser via the web build; Electron main process boots clean.

Task: docs/tasks/done/103-sync-pins-and-history-across-devices-with-new-tab.md
ADR: docs/adr/0017-shared-sync-backend-for-pins-and-history.md

[dokploy-2026-03-01-6ei3s7]

Dokploy Preview Deployment

Name	Status	Preview	Updated (UTC)
cdp-browser-app	✅ Done	Preview URL	2026-07-08T19:37:56.602Z