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/src/pages/Chat.tsx

@@ -0,0 +1,13 @@
+import { Sidebar } from '../components/Sidebar'
+import { MessagePane } from '../components/MessagePane'
+import { PeerList } from '../components/PeerList'
+
+export function Chat() {
+  return (
+    <div className="chat-layout">
+      <Sidebar />
+      <MessagePane />
+      <PeerList />
+    </div>
+  )
+}

web/src/pages/Onboarding.tsx

@@ -0,0 +1,35 @@
+import { useWaste } from '../store'
+
+interface Props {
+  status: 'disconnected' | 'connecting' | 'connected'
+}
+
+export function Onboarding({ status }: Props) {
+  const { send } = useWaste()
+
+  const label = status === 'connecting'
+    ? 'Connecting to daemon…'
+    : 'Waiting for daemon — is waste-daemon running?'
+
+  function joinNetwork(e: React.FormEvent<HTMLFormElement>) {
+    e.preventDefault()
+    const form = e.currentTarget
+    const name = (form.elements.namedItem('network') as HTMLInputElement).value.trim()
+    if (!name) return
+    send({ type: 'join_network', network_name: name })
+  }
+
+  return (
+    <div className="onboarding">
+      <h1>waste</h1>
+      <p className="status">{label}</p>
+
+      {status === 'connected' && (
+        <form onSubmit={joinNetwork} className="join-form">
+          <input name="network" placeholder="network name" autoComplete="off" autoFocus />
+          <button type="submit">Join</button>
+        </form>
+      )}
+    </div>
+  )
+}