Images were findable only by the filename someone typed. `media_assets` gives
them a title, caption, alt text, a category on the shared tree and tags, with a
weighted tsvector so they are searchable now (migration y7e8f9a0b1c2).
The embedding column is filled from the caption today. A vision-capable model can
fill it from the image itself later without another migration — and because
`embedding_model` stamps every vector, a text-embedded caption and a
vision-embedded image stay distinguishable instead of being silently mixed in one
index. Adding "media" to the embeddable kinds is all the retry task, the full
regeneration and the health report needed.
`media_tag_links.tag_id` carries no ORM-level foreign key: `question_tags` is
created by raw DDL rather than a model, so the constraint lives in the migration
where the table actually exists.
Tests: 113 backend green.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PpfzbZ1QTLMeVYxM2kyq8m
