feat: scaffold v2 with FastAPI, SQLite database, and project structure

Migrate from raw HTTPServer to FastAPI, add SQLite database with schema
for known objects, embeddings, events, and settings. Add centralized
config, Pydantic models, and 22 database integration tests.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/config.py

@@ -0,0 +1,56 @@
+"""Centralized configuration for frigate-notify v2."""
+
+import os
+
+
+class Config:
+    """Application configuration read from environment variables."""
+
+    # MQTT
+    MQTT_HOST: str = os.environ.get("MQTT_HOST", "192.168.86.192")
+    MQTT_PORT: int = int(os.environ.get("MQTT_PORT", "1883"))
+
+    # Frigate
+    FRIGATE_URL: str = os.environ.get("FRIGATE_URL", "http://192.168.86.192:5000")
+
+    # Matrix
+    MATRIX_HOMESERVER: str = os.environ.get(
+        "MATRIX_HOMESERVER", "http://192.168.86.192:8008"
+    )
+    MATRIX_ACCESS_TOKEN: str = os.environ.get("MATRIX_ACCESS_TOKEN", "")
+    MATRIX_ROOM_ID: str = os.environ.get("MATRIX_ROOM_ID", "")
+
+    # Vision - CLIP service
+    CLIP_SERVICE_URL: str = os.environ.get(
+        "CLIP_SERVICE_URL", "http://192.168.86.196:5200"
+    )
+
+    # Vision - Ollama
+    OLLAMA_URL: str = os.environ.get("OLLAMA_URL", "http://192.168.86.196:11434")
+    OLLAMA_MODEL: str = os.environ.get("OLLAMA_MODEL", "llava:13b")
+
+    # Recognition thresholds
+    RECOGNITION_THRESHOLD_HIGH: float = float(
+        os.environ.get("RECOGNITION_THRESHOLD_HIGH", "0.85")
+    )
+    RECOGNITION_THRESHOLD_LOW: float = float(
+        os.environ.get("RECOGNITION_THRESHOLD_LOW", "0.60")
+    )
+
+    # Filtering
+    ALLOWED_LABELS: set = set(
+        os.environ.get("ALLOWED_LABELS", "person,car,dog,cat,bird").split(",")
+    )
+    MIN_SCORE: float = float(os.environ.get("MIN_SCORE", "0.7"))
+    RATE_LIMIT_SECONDS: int = int(os.environ.get("RATE_LIMIT_SECONDS", "60"))
+    DEDUP_WINDOW_SECONDS: int = int(os.environ.get("DEDUP_WINDOW_SECONDS", "30"))
+
+    # Server
+    SERVER_HOST: str = os.environ.get("SERVER_HOST", "0.0.0.0")
+    SERVER_PORT: int = int(os.environ.get("SERVER_PORT", "5199"))
+
+    # Database
+    DB_PATH: str = os.environ.get("DB_PATH", "/data/frigate-notify.db")
+
+
+config = Config()