m.image events in delivered messages are fetched as the receiving Persona,
classified by magic bytes, bounded by size and header pixel count, and stored
under IMAGE_STORE_ROOT/<persona>/<room hash>/<bytes hash>[.ext] (0640, dirs
2750). The delivery tuple gains index 11, nil or [path, mime, size, sha256];
the pending kind becomes gamecult.persona.chat_pending.v2 with Huginn's v3
golden bytes. Refusals keep the typed text line plus a fixed-word reason.
The mouth test homeserver is answered in-process so the suite runs under a
capped address space.
Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>