Initial tablet POC: project restructure + WebSocket/HTTP server + JS client

- Restructured project into /app, /server, /client with run.py entry point
- WSServer (QWebSocketServer) with log_signal, start/stop, client tracking
- HTTP server serves /client on port 8080
- Vanilla JS client: faders, toggles, transport, drag-to-arrange, lock/save layout
- Start Tablet button + floating Tablet log window in app UI
- Preset broadcast on load/switch, DAW state relay, hardware sync via widget_update
- Widget colors synced from app palette, toggle state fixed (sends 0/127 correctly)
- Layout saved per preset UUID back to presets.json

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

app/styles.py

@@ -0,0 +1,32 @@
+FADER_STYLE = """
+    QSlider::groove:vertical {
+        background: #1e1e1e;
+        width: 8px;
+        border-radius: 4px;
+    }
+    QSlider::handle:vertical {
+        background: #bbbbbb;
+        border: 1px solid #222222;
+        height: 39px;
+        width: 24px;
+        margin: 0 -8px;
+        border-radius: 3px;
+    }
+    QSlider::handle:vertical:hover {
+        background: #dddddd;
+        border: 1px solid #111111;
+    }
+"""
+
+TITLE_STYLE = """
+    QLineEdit {
+        background-color: #000000;
+        border: none;
+        color: #ffffff;
+        font-weight: bold;
+        padding: 2px;
+    }
+    QLineEdit:focus {
+        border: 1px solid #555;
+    }
+"""