v27.0

mautrix-teams 27.0 aligns versioning with the underlying mautrix-go release
line; future patch releases will track it as 27.0.x. The release fixes the
meeting/group/channel naming gap, breaks a tight Trouter reconnect loop, and
stops the bridge re-inviting you to portals you have manually left.

Fixed

• Group, channel and meeting portals now pick up their Teams topic. The
  per-thread /v1/threads/<id> API returns thread metadata under the
  top-level properties key, while /conversations (used at startup)
  uses threadProperties; we now read either, and fall back to the
  calendar subject parsed from properties.meeting JSON for meeting
  threads where neither topic is set.
• Trouter /v4/a registration now refreshes the skype token on a 401 and
  retries once. Without this the bridge would enter a 5-second reconnect
  loop after Microsoft rotated the websocket and the cached skype token
  expired in the gap, hammering the auth endpoint until manual restart.
• Startup chat sync no longer re-invites you to portals you have manually
  left in Matrix. The bridge checks the room's member state and skips the
  resync when your membership is leave or ban. Live messages still
  trigger re-invite, as before.
• Unknown Teams contacts (no profile available, no cached display name)
  show as the bare AAD GUID instead of the full 8:orgid:<guid> MRI, and
  DM rooms with such contacts no longer get the bare MRI written into the
  room name; Element falls back to the ghost's display name instead.

Full Changelog: v26.04.2...v27.0