feat: add export_ipcd356 tool (kicad-cli, IPC-D-356 netlist)

New MCP tool `export_ipcd356` wrapping `kicad-cli pcb export ipcd356`:
generates an IPC-D-356 bare-board electrical-test netlist for flying-probe
and bed-of-nails testers. Minimal option set (outputPath + boardPath only,
matching the subcommand's --help). Self-contained interface handler reading
the saved .kicad_pcb.

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

src/tools/registry.ts

@@ -62,6 +62,7 @@ export const toolCategories: ToolCategory[] = [
       "export_drill",
       "export_ipc2581",
       "export_odb",
+      "export_ipcd356",
       "export_pdf",
       "export_svg",
       "export_3d",