By: Michael Lynch <git@mtlynch.io>
Show the add-comment form on media pages (m7-5)
Move the comments display into a reusable partial and add an always-visible
comment form below each media item's reactions, available to every signed-in
user.
The POST /m/{id}/comments endpoint intentionally returns HTTP 501 until the next
stacked commit persists comments.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>