v2.12.73 — NEW marker and navigation fixes

New mail reliability

• Dismissing NEW with X or Shift+N now saves an account-specific acknowledgement that stays consistent across windows and app restarts.
• N now waits for the required Inbox pages and moves to the same message boundary shown by the NEW divider.
• Pressing N while the Inbox is loading keeps the request and completes it when the destination is ready.
• If dismissing NEW cannot be saved, the marker stays visible with an inline Retry action.