Initial commit: MQTT to Clawdbot bridge

- Subscribe to MQTT topics, forward to Clawdbot webhook
- Configurable via environment variables
- Supports wake (system event) and agent (isolated) modes
- Includes systemd service template
- Home Assistant examples in README

.env.example

@@ -0,0 +1,14 @@
+# MQTT Configuration
+MQTT_URL=mqtt://your-broker:1883
+MQTT_USERNAME=
+MQTT_PASSWORD=
+MQTT_TOPICS=clawd/#,home/alerts/#
+MQTT_CLIENT_ID=clawdbot-bridge
+
+# Clawdbot Configuration
+CLAWDBOT_URL=http://127.0.0.1:18789
+CLAWDBOT_TOKEN=your-webhook-token-here
+CLAWDBOT_MODE=wake  # 'wake' for system events, 'agent' for isolated runs
+
+# Logging
+LOG_LEVEL=info  # debug, info, warn, error