POST /_journal/api/v1/images/alt writes the alt of a markdown post into
its source: the inline image  outside code
(classes.SetMarkdownImageAlt) or a raw img outside code
(classes.SetImageAltOutsideCode), so the next content save keeps it. An
image the markdown does not hold that way is refused with 422
changes.N.src and nothing is written.
- POST /_journal/api/v1/images/alt {dry_run, changes} sets alt on the
matching img of default or translated content through the tokenizer,
all or nothing (422), with a RecordSaved per changed post
- MCP journal_get_settings, journal_update_settings, journal_fix_headings
(manage_settings) and journal_set_image_alt (access_posts, destructive)
- journal:fix-headings help names its output and the refusal
- journal.Plugin.MCP: list_posts, show_post, list_categories, list_tags,
create_post, update_post, delete_post and the draft_post prompt, guard
backend, listed with golem15.journal.access_posts; update fields are
optional so only sent keys reach the route
- optionalBackendPrincipal honours the MCP dispatch marker (no bearer
short-circuit; anonymous reads unchanged)
- require summercms v0.4.4
- TestJournalMCPSmoke, TestOptionalBackendPrincipalDispatch
