feat(01-01): create package structure, Pydantic models, and device abstractions

- pyproject.toml with FastAPI, uvicorn, Pydantic v2, aiofiles, structlog deps
- DeviceConfig Pydantic model with StripType, UUID, validation constraints
- ShowModel with AudioRef, TrackModel, CueModel, AnalysisBlock, schema_version=1
- BaseDevice ABC with encode_frame, encode_animation_cmd, bytes_per_pixel
- SK6812Device (4 bytes/pixel) and WS2801Device (3 bytes/pixel) implementations

lightsync/models/device.py

@@ -0,0 +1,17 @@
+from uuid import UUID, uuid4
+from typing import Literal
+from pydantic import BaseModel, Field
+
+StripType = Literal["sk6812", "ws2801", "generic"]
+
+
+class DeviceConfig(BaseModel):
+    id: UUID = Field(default_factory=uuid4)
+    name: str
+    strip_type: StripType
+    led_count: int = Field(gt=0, le=1000)
+    ip: str
+    port: int = Field(ge=1, le=65535)
+    enabled: bool = True
+
+    model_config = {"populate_by_name": True}