Narrow the manifests-list projection behind a dedicated row type

ListContainerManifests projects the whole container_manifests row, annotations included, and the manifests-list resource does not serialize annotations (S17 §Resources, 8 fields). At the S12 cap an annotations payload is roughly 520 KB, so a max-size page reads about 53 MB to render about 30 KB, and database/sql clones the JSONB into the scan destination on the way.

The projection stayed whole in chore(datastore): add container manifest reads ... (!1131 - merged) • Hayley Swimelar • 19.3 because a partially populated ContainerManifest erases the documented difference between absent annotations and an empty object (method doc in internal/datastore/container_manifest.go at commit 408d821c). Dropping the column safely needs a list row type of its own with its own scanner. Do it alongside the jet conversion of this file's statements, so the table's row shapes churn once rather than twice.