refactor: serve MCP bundles under <name>/mcp with nginx guard; rename core->mcp_server

- collect.py: copy repo MCP bundles to ROOT/<name>/mcp (instead of ROOT/mcp/<name>); add nginx location guard to deny /<name>/mcp/
- config.py: bundle roots now point to <repo>/mcp and standards/mcp for static bundles
- Rename core.py -> mcp_server.py and update imports in main.py and registry.py
- Dockerfile: per-repo MCP COPYs under /app/<name>/mcp, drop blog copy; add ports 8008/8009 in .drone.yml
- Restore standards/mcp/libraries.json from git for registry server

Dockerfile

@@ -25,7 +25,7 @@ RUN pip install --no-cache-dir uv && \
     uv pip install --system -r requirements.txt
 
 # --- application files -----------------------------------------------------
-COPY main.py core.py config.py registry.py collect.py config.yml ./
+COPY main.py mcp_server.py config.py registry.py collect.py config.yml ./
 COPY nginx.conf /etc/nginx/conf.d/default.conf
 RUN rm -f /etc/nginx/sites-enabled/default