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/show.py

@@ -0,0 +1,46 @@
+from uuid import UUID, uuid4
+from datetime import datetime, timezone
+from typing import Any, Literal
+from pydantic import BaseModel, Field
+
+from lightsync.models.device import DeviceConfig
+
+
+class AudioRef(BaseModel):
+    source_type: Literal["file", "youtube"] = "file"
+    path: str | None = None
+    yt_url: str | None = None
+    duration_seconds: float | None = None
+
+
+class CueModel(BaseModel):
+    id: UUID = Field(default_factory=uuid4)
+    timestamp: float
+    mode: Literal["animation", "frame_sequence"] = "animation"
+    animation: str | None = None
+    params: dict[str, Any] = Field(default_factory=dict)
+
+
+class TrackModel(BaseModel):
+    device_id: UUID
+    cues: list[CueModel] = Field(default_factory=list)
+
+
+class AnalysisBlock(BaseModel):
+    analysed_at: datetime | None = None
+    tempo_bpm: float | None = None
+    beat_times: list[float] = Field(default_factory=list)
+    onset_times: list[float] = Field(default_factory=list)
+
+
+class ShowModel(BaseModel):
+    schema_version: int = 1
+    id: UUID = Field(default_factory=uuid4)
+    name: str
+    created_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
+    updated_at: datetime = Field(default_factory=lambda: datetime.now(timezone.utc))
+    audio: AudioRef = Field(default_factory=AudioRef)
+    devices: list[DeviceConfig] = Field(default_factory=list)
+    analysis: AnalysisBlock = Field(default_factory=AnalysisBlock)
+    tracks: list[TrackModel] = Field(default_factory=list)
+    ai_sequences: list[Any] = Field(default_factory=list)