feat: add export_odb tool (kicad-cli, ODB++ archive)

New MCP tool `export_odb` wrapping `kicad-cli pcb export odb`: precision,
compression mode (zip/tgz/none), and units. Single ODB++ job archive for
CAM/MES/assembly. 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

@@ -61,6 +61,7 @@ export const toolCategories: ToolCategory[] = [
       "export_gerbers",
       "export_drill",
       "export_ipc2581",
+      "export_odb",
       "export_pdf",
       "export_svg",
       "export_3d",