feat(runtime-worker): add VTStoreRegistry preloads

[kubohiroya]

Summary

• Add VTStoreRegistry and expose getVTStoreRegistry from runtime-worker.
• Register location/shape/route vector tile stores from register*WorkerStores instead of leaving them as no-op.
• Run plugin worker store preloads during worker bootstrap and document the VTStoreRegistry path.

Validation

• pnpm --filter @hierarchidb/runtime-worker exec vitest run src/entity/__tests__/unit/VTStoreRegistry.unit.ts
• pnpm --filter @hierarchidb/location-plugin exec vitest run src/worker/__tests__/unit/registerLocationWorkerStores.unit.test.ts src/worker/__tests__/unit/createLocationVectorTileStoreDexie.unit.test.ts
• pnpm -w turbo run typecheck --filter @hierarchidb/runtime-worker --filter @hierarchidb/location-plugin --filter @hierarchidb/shape-plugin --filter @hierarchidb/route-plugin --filter @hierarchidb/app
• pnpm tsx scripts/naming-audit.ts --changed-since origin/main --format json --report-only
• pnpm --filter @hierarchidb/shape-plugin typecheck
• pnpm --filter @hierarchidb/shape-plugin build

Closes #1507