Type Alias TemplateSnapshotAnnotation

At most one link per annotation (unique on annotation_id); null for non-contact annotations.

annotations.is_exclusive, frozen with the rest of the template.

OPTIONAL, not required: every snapshot written before the column existed simply has no such key, and declaring it required would be a lie the type system would then let callers rely on. undefined and null both mean "not recorded", which is what sends the fill back to the regex fallback. Adding a key does NOT bump TEMPLATE_SNAPSHOT_VERSION — that constant gates parseTemplateSnapshot, so bumping it would make every existing run unreadable.