Add 5 MCP tools (PatternImportMixin) and 1 prompt for importing external antenna pattern data. Pure-Python parsers with IDW interpolation on the sphere, single-cut-to-3D synthesis for EMCAR/2-col CSV, and Touchstone S1P bridge to the analytical pattern engine. Web UI gets a "Load File" button with multipart upload endpoint and WebSocket broadcast. 78 tools, 14 prompts.