render: add dockerCommand and fix gateway port config

- Add dockerCommand to start gateway with --bind lan --port 8080
- Replace unused INTERNAL_GATEWAY_PORT with CLAWDBOT_GATEWAY_PORT
- Gateway now properly starts on port 8080 for Render's HTTP proxy

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

render.yaml

@@ -4,9 +4,12 @@ services:
     runtime: docker
     plan: starter
     healthCheckPath: /health
+    dockerCommand: node dist/index.js gateway --bind lan --port 8080 --allow-unconfigured
     envVars:
       - key: PORT
         value: "8080"
+      - key: CLAWDBOT_GATEWAY_PORT
+        value: "8080"
       - key: SETUP_PASSWORD
         sync: false
       - key: CLAWDBOT_STATE_DIR