Support parsing: vcpkg-lock.json registry lock metadata #366
Description
Follow-up issue for vcpkg-lock.json support after the main vcpkg.json manifest parser lands.
Current status covered elsewhere:
- vcpkg.json manifest identity and direct dependency extraction
- embedded/sibling configuration metadata preservation
Remaining work:
- decide whether vcpkg-lock.json should be parsed as first-class scan output or intentionally deferred
- if supported, preserve registry-resolution lock metadata with a clear provenance model
- decide whether locked registry references should influence dependency/resolved-package output or remain extra_data only
Related umbrella issue: #342