Adds add_hierarchical_sheet (insert a sheet symbol referencing a child
.kicad_sch, with sheet_instances + fixed component instance paths) and
create_hierarchical_subsheet (create the child file + wire it into the parent
in one call). Upstream has add_sheet_pin / add_schematic_hierarchical_label
but no way to create a sheet or stand up a child sheet, so hierarchical
designs can't be built through the MCP server today.
- python/commands/schematic_hierarchy.py: SchematicHierarchyCommands
- src/tools/schematic-hierarchy.ts + registry 'schematic_hierarchy' category
- python/kicad_interface.py: import + instantiate + dispatch routes
- tests/test_schematic_hierarchy.py: 5 unit/integration tests on real .kicad_sch
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>