63d1f6a6

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>