feat: add export_sch_svg tool (kicad-cli, schematic SVG)

New MCP tool `export_sch_svg` wrapping `kicad-cli sch export svg`: outputs
one SVG per page into a directory. Exposes drawing-sheet override, theme,
B&W, exclude-drawing-sheet, default-font, no-background-color, and page
selection. schematicPath required; directory output uses outputDir.

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

src/tools/registry.ts

@@ -72,6 +72,7 @@ export const toolCategories: ToolCategory[] = [
       "export_3d_cli",
       "export_sch_bom",
       "export_sch_pdf",
+      "export_sch_svg",
       "export_pdf",
       "export_svg",
       "export_3d",