feat: initial KosmoConnect platform v0.1

Includes:
- Backend services: ingestion (:8001), weather API (:8002),
  gateway (:8003), billing (:8004) with BTCPay integration
- Shared asyncpg pool, TimescaleDB hypertable, Redis, Mosquitto MQTT
- React frontend: Dashboard (MapLibre) and Messaging (chat UI)
- Bridge daemon for Pi + Meshtastic (Serial/TCP T-Deck support)
- Production Docker Compose, Nginx reverse proxy, ops scripts
- DEPLOY.md with step-by-step deployment guide

backend/shared/db.py

@@ -0,0 +1,11 @@
+import os
+import asyncpg
+
+DB_DSN = os.getenv(
+    "DATABASE_URL",
+    "postgresql://kosmo:kosmo_dev_pass@localhost:5432/kosmoconnect"
+)
+
+
+async def get_pool() -> asyncpg.Pool:
+    return await asyncpg.create_pool(DB_DSN, min_size=2, max_size=10)