I1: query the attachments themselves author-restricted when the user
lacks edit_others_posts (PostGuard::ownPostsOnly, extracted from
ContentQueryAbility so content-query reuses the exact same rule)
instead of relying solely on a post-query editable() filter, which
could leak the existence of other users' attachments via an empty
page plus next_cursor. editable() stays as a backstop.
Also: M1 document that only status=inherit attachments are listed;
M2 tie-break ordering by ID (content-query and media-search) for
stable pagination; M3 no next_cursor once the last candidate was
examined; M4 reject an explicit non-image mime with missing_alt;
M5 additional coverage (posts_per_page, cursor offset pass-through,
invalid cursor, post_status/date/mime args); mime maxLength 100.
Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7
janniclas.loosenandClaude Opus 5.5
b0da2cdecc