Study: what upstream's Project View can teach the fork #831

Study, no code: upstream's Project View (ee65652 and follow-ups 3028edd, 47da490, 889908e, 025daed) is not ported as such (decided by JB, 2026-10-28): it is a second navigation model, deletes schedule-ipc.js, rewrites the schedule runner and duplicates the What's new dialog.

Read it for what it teaches the fork: interactions, state handling, scheduling, worktree deletion (it lists the folders a deletion removes), done-track collapsing, snooze, previews. For each idea, say which existing fork feature it would improve, how, and the cost. Output: a report with one proposed issue per worthwhile idea.