existing_principals() ran for every doc type when seeding acl_principals.
note/news_item/deck_card IDs are per-user (not globally unique) and chunk
point IDs are user-agnostic, so on an ID collision the merge would pull in
another user's principal and cross-surface their content via the
acl_principals search branch. It was also N wasted tenant-wide scrolls on
initial sync for those types. Gate the prior-principal merge on
doc_type == "file" (the only type with cross-user dedup + globally-unique
fileid); other types seed with the indexer only.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
