v1.40.0

feat(ws): list a repo's plain windows as their own rows, and close one with d d

In dg ws, a repo with extra tmux windows (say a node window and a zsh
window next to its worktree) showed a single row named after the session,
usually the same name as the repo. Enter on it reached only the first of those
windows. The rest could not be seen or picked. Each plain window now gets its
own row under the repo, named by the window.

• One row per plain window, before the repo's worktree rows. The session name
  is no longer shown, because the repo header already says where you are.
• Enter switches to that exact window. Rows are keyed by tmux's window id, not
  the window's name: tmux auto-names every shell zsh, and a name lookup could
  land in the wrong window.
• d d on a window row closes that window only. Its session and the other
  windows in it stay.
• n on a window row (or a pane row under it) offers that repo first in the
  picker, as it already did from a worktree row.
• The dashboard opens with the cursor on the window you came from.

Behavior changes: the repo-session row is gone. $ (rename session) no longer
works from a repo's rows. Use tmux's own keys, or $ on a standalone session
row. d d from a repo's row used to close all of that session's plain windows.
It now closes only the window under the cursor.

Full Changelog: v1.39.0...v1.40.0