feat: standalone web UI (React + Vite)

React + TypeScript UI on port 5274. Connects to local daemon via
WebSocket IPC (DaemonAdapter). Full chat layout with sidebar, message
pane, and peer list. Mirrors the TUI feature set.

- src/types.ts        — IPC types mirroring proto.go
- src/adapter/daemon  — WebSocket IPC adapter with auto-reconnect
- src/store/index.ts  — Zustand store; handles all daemon events
- src/pages/          — Onboarding (connect + join) and Chat
- src/components/     — Sidebar, MessagePane, PeerList

Dev: cd web && npm run dev  (port 5274)
Build: cd web && npm run build

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

web/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "files": [],
+  "references": [
+    { "path": "./tsconfig.app.json" },
+    { "path": "./tsconfig.node.json" }
+  ]
+}