#20430 cmux-next: the steady attention ring is clearly visible and swells once (opt-in); the default ring stays

Lawrence's call (via Leo, 2026-10-14): no attention ring by default. A pane that needs attention draws no ring. The sidebar status glyph, the tab mark and the Dock badge carry the attention. The ring stays an opt-in setting (notifications.attention.style):

• steady: clearly visible at 0.75 opacity with one 0.3 s soft swell on arrival, no blink. A further notification swells from that level instead of dropping out first.
• blink: unchanged.
• pulse: unchanged.

Default goes from blink to none. The settings schema, MDM docs and the defaults snapshot are regenerated.

Verification

• swift test --filter AttentionDefaultTests: red at 460c188cc32 (the default was .steady), green at d1b4c4dbb35.
• swift test --filter AttentionSteadyTests: red at 8b94e85e65e (the ring rested at 0.4 with no swell), green at 8bb37133d99. Covers the 0.75 rest, one small fast swell, the Reduce Motion fade, and no drop-out on a further notification.
• 11 attention, export and MDM tests pass.

Recording

• Default (no ring): there is no ring around the pane. The sidebar row shows "1 · finished" and the tab has the unread dot.
  
• Opt-in steady vs the old blink, side by side. The steady ring rises to brightness 162 at 0.1 s, settles at 133 by 0.27 s, and a second notification goes 133→162→133 without dropping below 133. The old blink settled at 88.
  

Changelog

Changed: panes that need attention no longer draw a ring by default; the sidebar and tab marks show it, and the ring is an opt-in setting (steady or blink).

🤖 Generated with Claude Code