Label image with org.opencontainers.image.source for Gitea repo linking

Gitea attaches a container package to its repo via this OCI label; without it
the pushed image shows up unlinked under the user's packages instead of the
ag-bids-mcp repo's Packages tab.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Dockerfile

@@ -1,5 +1,12 @@
 FROM python:3.12-slim
 
+# Links this container package to its Gitea repo (Gitea reads
+# org.opencontainers.image.source to attach the package to the repo's
+# Packages tab). Without it the image shows up unlinked under the user.
+LABEL org.opencontainers.image.source="https://git.jpaul.io/justin/ag-bids-mcp" \
+      org.opencontainers.image.title="ag-bids-mcp" \
+      org.opencontainers.image.description="MCP server exposing ag-monitor commodity price data"
+
 ENV PYTHONDONTWRITEBYTECODE=1 \
     PYTHONUNBUFFERED=1 \
     PIP_NO_CACHE_DIR=1