CollaborationFollowersProvider implements core RecordFollowersProviderInterface
over collaboration_follow (CHANGE/ALERT -> notifyOnChange, COMMENT ->
notifyOnComment, muted excluded), registered via RecordFeaturesMetaData, so
qbit-alerts can notify followers. Cached favorite/recent labels are stored
only when FieldAccessHelper.isRecordLabelFullAccess holds; notification
titles fall back to the table label and id for recipients without FULL
label access. Timeline masking (MASKED shows the mask, HIDDEN omitted,
canary never leaks) is covered by tests.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>