v0.4.0

Changelog

Other

• 1e1a473 Merge branch 'worktree-agent-ae787cda3b1a5f13b'
• 9ca0e4e perf: geometry cache — msgGeom is O(1) across j/k selection moves
• a1f2c5e presence: real dots for DM partners via 60s poll
• f9befcb v0.4.0: real presence + cached message-pane geometry + bounded reads