mAIndmeld 0.5.1: room page polish

Added

• Room page: the Invite box gains a model row (configured profiles, with
  those in the room marked and the health hint shown) and a call-a-human
  row; the lobby's create form lists profiles as checkboxes (#46). Health's
  profile report carries display_name.
• Room page: messages and the note page render Markdown with a small
  dependency-free renderer that escapes first (#43); @mentions of
  participants are highlighted and clickable, with the card tinted when
  the signed-in person is named (#41); typing @ in the composer
  autocompletes participants (#42); the room takes the window's width
  while prose keeps a readable measure (#45).

Images:

• ghcr.io/dev-dull/maindmeld:0.5.1@sha256:3eeb1300d6db634476bf5d78e2276fe5595f4179b907c9a377527f5197f262f9
• ghcr.io/dev-dull/maindmeld-runner:0.5.1@sha256:23d79160f17a9c6f101f726da4f6dfa10bdf6fa69dce07adf63089e89d12cb2d