P6-R1: Audio/video streaming pipeline

- src/streaming/ module: camera detection (USB webcam + Pi Camera Module via
  v4l2/libcamera), GStreamer pipeline builder with V4L2/OMX/x264 h264 encoders,
  platform presets (YouTube, Twitch, Facebook, custom RTMP), streamer lifecycle
  manager with auto-reconnect, scene management, stream statistics
- Keyboard shortcut controller (evdev + pynput fallback) for stream control:
  Ctrl+Shift+S (start/stop), Ctrl+Shift+1-9 (scene switch), Ctrl+Shift+R (reconnect)
- REST API: /api/v1/stream/* endpoints for start/stop/status, scenes, cameras,
  platforms, and hotkey listing — integrated into NetworkServer
- StreamStateProvider bridging layer connects REST routes to Streamer instance
- GStreamer pipeline supports ALSA/JACK/PulseAudio audio capture and
  V4L2/libcamera video capture with H.264 hardware encoding on RPi4B
- Low-latency streaming settings for live performance (zerolatency, no B-frames)
- 89 streaming tests (709 total project tests pass)

web/style.css

@@ -797,6 +797,89 @@ input, button, select, textarea {
 .session-card-actions button.danger { color: var(--danger); }
 .session-card-actions button.danger:hover { background: var(--danger); color: var(--text); }
 
+/* Session card info line */
+.session-card-info {
+    font-size: var(--font-size-xs);
+    color: var(--text-faint);
+    margin-top: 0.15rem;
+}
+
+/* Session card badges */
+.badge {
+    display: inline-block;
+    padding: 0.1rem 0.3rem;
+    font-size: 0.55rem;
+    background: var(--bg-alt);
+    border: 1px solid var(--border);
+    border-radius: 3px;
+    color: var(--text-dim);
+    vertical-align: middle;
+}
+.badge.active {
+    background: var(--connected);
+    color: var(--bg);
+    border-color: var(--connected);
+}
+
+/* Current snapshot card highlight */
+.session-card.current {
+    border-color: var(--accent);
+    box-shadow: 0 0 4px var(--accent-dim);
+}
+
+/* Sessions subtabs */
+.sessions-subtabs {
+    display: flex;
+    gap: 0px;
+    border-bottom: 1px solid var(--border);
+    flex-shrink: 0;
+}
+.subtab {
+    padding: 0.35rem 0.75rem;
+    font-size: var(--font-size-xs);
+    background: none;
+    color: var(--text-dim);
+    border: none;
+    border-bottom: 2px solid transparent;
+    cursor: pointer;
+    min-height: var(--touch-min);
+    transition: color 0.15s, border-color 0.15s;
+}
+.subtab:hover { color: var(--text); }
+.subtab.active { color: var(--accent); border-bottom-color: var(--accent); }
+
+/* Auto-save status */
+.autosave-status {
+    padding: 0.25rem 0.5rem;
+    font-size: var(--font-size-xs);
+    color: var(--text-faint);
+    flex-shrink: 0;
+}
+
+/* Setlist entry row */
+.setlist-entry-row {
+    display: flex;
+    align-items: center;
+    gap: 0.5rem;
+    padding: 0.35rem 0.5rem;
+    background: var(--bg-alt);
+    border: 1px solid var(--border);
+    border-radius: 4px;
+    margin-bottom: 0.3rem;
+    font-size: var(--font-size-sm);
+}
+.setlist-entry-row span { flex: 1; }
+.setlist-entry-row button {
+    padding: 0.2rem 0.4rem;
+    background: var(--btn-bg);
+    color: var(--danger);
+    border: 1px solid var(--border);
+    border-radius: 3px;
+    cursor: pointer;
+    min-height: 28px;
+    font-size: var(--font-size-xs);
+}
+
 /* ── Modal (EQ) ────────────────────────────────────────────────────────── */
 .modal {
     position: fixed;