fix: increase healthcheck start-period to 180s

Gateway ready timeout is 120s but healthcheck start-period was 90s.
With heavier image (Chromium + JupyterLab), container took longer
than 90s to become ready causing premature 503 → HF restart loop.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Dockerfile

@@ -97,7 +97,7 @@ ENV HERMES_HOME=/opt/data \
 
 EXPOSE 7861
 
-HEALTHCHECK --interval=30s --timeout=5s --start-period=90s \
+HEALTHCHECK --interval=30s --timeout=5s --start-period=180s \
   CMD curl -fsS http://localhost:7861/health || exit 1
 
 CMD ["/opt/huggingmes/start.sh"]