Initial Aurora Core 0.1 implementation

Production-grade media metadata backend per docs/aurora-core-spec.md:
Aurora-owned UUIDv7 identity system, normalized movie/TV/people/credits
schema, provider abstraction with a TMDb adapter, an idempotent async
ingestion pipeline (normalize -> match -> upsert -> provenance), a
Postgres FTS/trigram search layer, a stateless FastAPI v1 API with
Redis caching/rate-limiting, arq workers, dev/prod Docker Compose
topologies, unit + integration + load tests, CI, and architecture/
database/API/ERD documentation.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

app/api/deps.py

@@ -0,0 +1,37 @@
+"""Shared FastAPI dependencies and helpers for the v1 API."""
+
+from __future__ import annotations
+
+from collections.abc import Awaitable, Callable
+
+from fastapi import HTTPException, status
+from pydantic import BaseModel
+from redis.asyncio import Redis
+
+from app.services.cache import cache_get_json, cache_set_json
+
+
+def not_found(entity_type: str, aurora_id_str: str) -> HTTPException:
+    return HTTPException(
+        status_code=status.HTTP_404_NOT_FOUND,
+        detail={"code": f"{entity_type}_not_found", "message": f"No such {entity_type}: {aurora_id_str}"},
+    )
+
+
+async def cached_response[T: BaseModel](
+    redis: Redis,
+    key: str,
+    model: type[T],
+    loader: Callable[[], Awaitable[T]],
+    ttl: int | None = None,
+) -> T:
+    """Serve `model` from Redis if present, otherwise call `loader`, cache
+    the result, and return it. Fails open to `loader` on any cache error."""
+
+    cached = await cache_get_json(redis, key)
+    if cached is not None:
+        return model.model_validate(cached)
+
+    result = await loader()
+    await cache_set_json(redis, key, result.model_dump(mode="json"), ttl=ttl)
+    return result