Bump kicad submodule to the per-item uuid identity change, plus the wasm/test
infra to verify it:
- wasm/bindings/pl_editor_embind.cpp: test-only kicadSaveDrawingSheet(path) hook
that serializes the singleton DS_DATA_MODEL to MEMFS (also a building block for
the bridge's later materialize-to-file path)
- tests/kicad/pl_editor-uuid.spec.ts: open->save->read-back e2e proving (uuid …)
backfill (4 distinct uuids) and load->save round-trip preservation
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>