Add user-selectable inbox sorting by sender, subject, size, and date

The submitted context

Gmail search can now order results by Most relevant or Most recent, but Gmail still lacks broader user-selectable sorting for Inbox and labels and richer grouping within search results. Reviewing a crowded mailbox by sender, subject, attachment size, thread size, or oldest-first date still requires constructing queries rather than choosing a persistent sort. Please add a reversible Sort by control for sender, recipient, subject, newest or oldest date, attachment size, unread state, and thread size. It should work inside Inbox, labels, categories, and search results without moving messages or changing labels. Evidence reviewed 2026-08-09: https://support.google.com/mail/answer/7190 https://support.google.com/mail/answer/6593