feat: footer, auto-pause on no viewers, and Redsys question submissions

- Footer: add site-footer with one-liner + Cloud Host branding linking to cloudhost.es (mobile only, hidden on desktop)
- Auto-pause: game pauses automatically after AUTOPAUSE_DELAY_MS (default 60s) with no viewers connected; auto-resumes when first viewer connects; shows "Esperando espectadores…" in the UI
- Redsys: new /pregunta page lets viewers pay 1€ via Redsys to submit a fill-in question; submitted questions are used as prompts in the next round instead of AI generation; new redsys.ts implements HMAC_SHA256_V1 signing (3DES key derivation + HMAC-SHA256); notification endpoint at /api/redsys/notificacion handles server-to-server confirmation
- db.ts: questions table with createPendingQuestion / markQuestionPaid / getNextPendingQuestion / markQuestionUsed
- .env.sample: added AUTOPAUSE_DELAY_MS, PUBLIC_URL, REDSYS_* vars

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

pregunta.css

@@ -0,0 +1,187 @@
+/* ── Reset & Variables ────────────────────────────────────────── */
+
+*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
+
+:root {
+  --bg: #0a0a0a;
+  --surface: #111;
+  --border: #1c1c1c;
+  --text: #ededed;
+  --text-dim: #888;
+  --text-muted: #444;
+  --accent: #D97757;
+  --sans: 'Inter', -apple-system, sans-serif;
+  --mono: 'JetBrains Mono', 'SF Mono', monospace;
+}
+
+body {
+  background: var(--bg);
+  color: var(--text);
+  font-family: var(--sans);
+  font-size: 14px;
+  line-height: 1.5;
+  -webkit-font-smoothing: antialiased;
+  min-height: 100vh;
+  min-height: 100dvh;
+}
+
+/* ── Layout ────────────────────────────────────────────────────── */
+
+.pregunta {
+  min-height: 100vh;
+  min-height: 100dvh;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  padding: 32px 20px;
+}
+
+.pregunta__panel {
+  width: 100%;
+  max-width: 480px;
+  display: flex;
+  flex-direction: column;
+  gap: 20px;
+}
+
+/* ── Logo ──────────────────────────────────────────────────────── */
+
+.pregunta__logo {
+  display: inline-flex;
+  text-decoration: none;
+  margin-bottom: 4px;
+}
+
+.pregunta__logo img {
+  height: 20px;
+  width: auto;
+}
+
+/* ── Typography ────────────────────────────────────────────────── */
+
+.pregunta__panel h1 {
+  font-size: 22px;
+  font-weight: 700;
+  line-height: 1.3;
+}
+
+.pregunta__sub {
+  color: var(--text-dim);
+  font-size: 14px;
+}
+
+/* ── Form ──────────────────────────────────────────────────────── */
+
+.pregunta__form {
+  display: flex;
+  flex-direction: column;
+  gap: 12px;
+}
+
+.pregunta__label {
+  font-size: 13px;
+  font-weight: 500;
+  color: var(--text-dim);
+}
+
+.pregunta__textarea {
+  width: 100%;
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  padding: 12px;
+  color: var(--text);
+  font-family: var(--sans);
+  font-size: 14px;
+  line-height: 1.5;
+  resize: vertical;
+  min-height: 88px;
+  transition: border-color 0.15s;
+}
+
+.pregunta__textarea:focus {
+  outline: none;
+  border-color: #444;
+}
+
+.pregunta__textarea::placeholder {
+  color: var(--text-muted);
+}
+
+.pregunta__hint {
+  font-size: 12px;
+  color: var(--text-muted);
+  font-family: var(--mono);
+}
+
+/* ── Error ─────────────────────────────────────────────────────── */
+
+.pregunta__error {
+  background: rgba(220, 60, 60, 0.08);
+  border: 1px solid rgba(220, 60, 60, 0.25);
+  border-radius: 6px;
+  padding: 10px 14px;
+  color: #ff6b6b;
+  font-size: 13px;
+}
+
+/* ── Submit ────────────────────────────────────────────────────── */
+
+.pregunta__submit {
+  padding: 12px 20px;
+  background: var(--accent);
+  border: none;
+  border-radius: 8px;
+  color: #fff;
+  font-size: 14px;
+  font-weight: 600;
+  cursor: pointer;
+  font-family: var(--sans);
+  transition: opacity 0.15s;
+}
+
+.pregunta__submit:hover:not(:disabled) {
+  opacity: 0.85;
+}
+
+.pregunta__submit:disabled {
+  opacity: 0.35;
+  cursor: not-allowed;
+}
+
+/* ── Status button (ok/ko states) ──────────────────────────────── */
+
+.pregunta__btn {
+  display: inline-block;
+  padding: 12px 20px;
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: 8px;
+  color: var(--text);
+  font-size: 14px;
+  text-decoration: none;
+  text-align: center;
+  transition: border-color 0.15s;
+}
+
+.pregunta__btn:hover {
+  border-color: #444;
+}
+
+/* ── Quick links ───────────────────────────────────────────────── */
+
+.pregunta__links {
+  display: flex;
+  gap: 16px;
+  justify-content: center;
+}
+
+.pregunta__links a {
+  color: var(--text-muted);
+  text-decoration: none;
+  font-size: 13px;
+}
+
+.pregunta__links a:hover {
+  color: var(--text-dim);
+}