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/colorswatchpopup.py

@@ -0,0 +1,31 @@
+from PyQt6.QtWidgets import QWidget, QHBoxLayout, QPushButton
+from PyQt6.QtCore import Qt
+from palette import PALETTE
+
+class ColorSwatchPopup(QWidget):
+    def __init__(self, callback, parent=None):
+        super().__init__(parent, Qt.WindowType.Popup)
+        self.callback = callback
+        layout = QHBoxLayout(self)
+        layout.setContentsMargins(4, 4, 4, 4)
+        layout.setSpacing(4)
+        for name, hex_color in PALETTE:
+            btn = QPushButton()
+            btn.setFixedSize(22, 22)
+            btn.setStyleSheet(f"""
+                QPushButton {{
+                    background-color: {hex_color};
+                    border-radius: 3px;
+                    border: 1px solid rgba(255,255,255,0.2);
+                }}
+                QPushButton:hover {{
+                    border: 2px solid #00ff88;
+                }}
+            """)
+            btn.clicked.connect(lambda checked, n=name, c=hex_color: self.pick(n, c))
+            layout.addWidget(btn)
+        self.setStyleSheet("background-color: #2d2d2d; border-radius: 4px;")
+
+    def pick(self, name, hex_color):
+        self.callback(name, hex_color)
+        self.close()