feat(01-01): create device registry, show store, FastAPI app, API routes, and frontend shell

- DeviceRegistry with load/save/add/remove/instantiate and _DEVICE_CLASSES dict
- ShowStore with save/load/list_ids using aiofiles for async I/O
- FastAPI app with lifespan hook (startup: load registry/store, shutdown: save registry)
- API routes: GET/POST /api/devices/, DELETE /api/devices/{id}, GET/POST /api/shows/, GET /api/shows/{id}
- WebSocket stub at /ws with ConnectionManager and ack echo
- Frontend shell: DAW layout with header, sidebar (DEVICES + ANIMATIONS), TIMELINE, TRANSPORT
- Terminal aesthetic: dark theme, cyan accents, monospace fonts, no drop shadows
- .gitignore for runtime data (devices.json, shows/, __pycache__, .venv)

lightsync/devices/registry.py

@@ -0,0 +1,55 @@
+import json
+import aiofiles
+from pathlib import Path
+from lightsync.models.device import DeviceConfig
+from lightsync.devices.base import BaseDevice
+from lightsync.devices.sk6812 import SK6812Device
+from lightsync.devices.ws2801 import WS2801Device
+
+# Registry of strip_type -> device class (INF-02: add new type here only)
+_DEVICE_CLASSES: dict[str, type[BaseDevice]] = {
+    "sk6812": SK6812Device,
+    "ws2801": WS2801Device,
+}
+
+
+class DeviceRegistry:
+    def __init__(self, path: Path):
+        self._path = path
+        self._devices: dict[str, DeviceConfig] = {}  # id (str) -> config
+
+    async def load(self) -> None:
+        if self._path.exists():
+            async with aiofiles.open(self._path) as f:
+                raw = json.loads(await f.read())
+            self._devices = {
+                d["id"]: DeviceConfig.model_validate(d)
+                for d in raw.get("devices", [])
+            }
+
+    async def save(self) -> None:
+        data = {"devices": [d.model_dump(mode="json") for d in self._devices.values()]}
+        async with aiofiles.open(self._path, "w") as f:
+            await f.write(json.dumps(data, indent=2))
+
+    def add(self, config: DeviceConfig) -> None:
+        self._devices[str(config.id)] = config
+
+    def remove(self, device_id: str) -> bool:
+        return self._devices.pop(device_id, None) is not None
+
+    def get(self, device_id: str) -> DeviceConfig | None:
+        return self._devices.get(device_id)
+
+    def list_all(self) -> list[DeviceConfig]:
+        return list(self._devices.values())
+
+    def instantiate(self, device_id: str) -> BaseDevice | None:
+        """Create a live BaseDevice instance from stored config."""
+        config = self.get(device_id)
+        if config is None:
+            return None
+        cls = _DEVICE_CLASSES.get(config.strip_type)
+        if cls is None:
+            raise ValueError(f"Unknown strip_type: {config.strip_type}")
+        return cls(config)