excalidraw-mcp-lives-at-opt-mcp-servers-not-opt-infra

Architecture.md incorrectly listed the Excalidraw MCP server as being at /opt/infra/. The actual path is /opt/mcp-servers/excalidraw-mcp/. Infra services at /opt/infra/ are infrastructure components; MCP servers live at /opt/mcp-servers/. These two directories serve different roles and should not be conflated in documentation.