adr-0048-studio-editor-package-scope.md

@objectstack/objectql	patch
@objectstack/rest	patch

fix(metadata): package-scope the layered (Studio editor) read via ?package= (ADR-0048)

The ?layers=true single-item read (the Studio metadata editor's 3-state code/overlay/effective view) ignored packageId, so editing one of two same-named items from different packages resolved ambiguously (first match).

• protocol.getMetaItemLayered now threads packageId into the code layer (metadataService.get + lookupArtifactItem + registry.getItem) and the sys_metadata overlay query (package_id prefer-local).
• registry.getArtifactItem(type, name, currentPackageId?) and lookupArtifactItem gained the optional package-scope hint.
• rest-server threads ?package= into the layered branch.

This completes the per-route package-scoped resolution audit: the runtime render surface (dashboard/report/page/doc) was already scoped; this closes the Studio editor (/apps/:appName/metadata/:type/:name). Frontend counterpart sends ?package= from the metadata list row's owning package.