Initial commit — DRB server stack

Includes c2-core (FastAPI/MQTT/Firestore), discord-bot (slash commands),
frontend (Next.js admin UI), and mosquitto config.

drb-c2-core/.env.example

@@ -0,0 +1,21 @@
+# MQTT broker (usually the mosquitto container on this host)
+MQTT_BROKER=mosquitto
+MQTT_PORT=1883
+MQTT_USER=
+MQTT_PASS=
+
+# GCP — path to service account JSON inside the container
+GCP_CREDENTIALS_PATH=/app/gcp-key.json
+
+# Firestore database name (use "(default)" if you didn't create a named database)
+FIRESTORE_DATABASE=c2-server
+
+# GCS bucket for audio storage
+GCS_BUCKET=your-bucket-name
+
+# How long (seconds) before a node is marked offline if no checkin received
+NODE_OFFLINE_THRESHOLD=90
+
+# Auth — static key that edge nodes send as Bearer token on /upload
+# Generate with: openssl rand -hex 32
+NODE_API_KEY=