new changes

docs/ubuntu-dev-install.md

@@ -43,6 +43,24 @@ make down
 - NATS monitor: `http://localhost:8222`
 - MinIO console: `http://localhost:9001`
 
+## Troubleshooting
+
+### `permission denied while trying to connect to the docker API`
+
+After adding your user to the `docker` group, your **current** shell may not see that group until you log out and back in. Install scripts use `scripts/docker-compose.sh`, which runs Compose via `sg docker` when needed so the first run succeeds without a re-login.
+
+If you still see the error, run:
+
+```bash
+newgrp docker
+```
+
+or log out and SSH in again, then:
+
+```bash
+bash scripts/docker-compose.sh up -d --build
+```
+
 ## Notes
 - This is a development scaffold for the architecture implementation.
 - `panel-api` currently serves a minimal runtime entrypoint for health and bootstrap validation.