MVP: Go daemon, password auth, persistent PTY terminals, React/xterm UI, PWA

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

web/src/Login.tsx

@@ -0,0 +1,28 @@
+import { FormEvent, useState } from 'react'
+import { api } from './api'
+
+export default function Login({ onLogin }: { onLogin: () => void }) {
+  const [pw, setPw] = useState('')
+  const [err, setErr] = useState('')
+  const [busy, setBusy] = useState(false)
+
+  async function submit(e: FormEvent) {
+    e.preventDefault()
+    setBusy(true); setErr('')
+    try { await api.login(pw); onLogin() }
+    catch (e) { setErr(e instanceof Error ? e.message : 'login failed') }
+    finally { setBusy(false) }
+  }
+
+  return (
+    <div className="center">
+      <form className="login" onSubmit={submit}>
+        <h1>Hamlet</h1>
+        <input type="password" autoFocus autoComplete="current-password" placeholder="password"
+          value={pw} onChange={(e) => setPw(e.target.value)} />
+        <button disabled={busy || !pw}>{busy ? '…' : 'Sign in'}</button>
+        {err && <div className="error">{err}</div>}
+      </form>
+    </div>
+  )
+}