T29: inside herdr the right column follows herdr's focused pane: herdr keeps its panes' OSC 7, so on macOS and Linux a session that finds herdr's client leading its pty's foreground reads the focused pane's folder from herdr's socket, found as herdr 0.9 finds it

tasks/acceptance.md

@@ -51,6 +51,7 @@ What no check reached: no one has looked at the window on Windows, which CI buil
 |---|---|---|---|
 | PTY through alacritty's event loop; OSC 7 scanned on the reader | T04 | `term::pty`, `term::tap` tests; round 3 failed at the cap, its fix stands on a red-green test | Pass |
 | Shell integration for zsh, bash, fish, PowerShell; a shell without it reports nothing and the panels say so | T05 | `term::shell` tests on macOS and Linux | Pass |
+| Inside herdr, the folder of herdr's focused pane, read from its socket, on macOS and Linux | T29 | `term::herdr` tests: the socket found as herdr 0.9 finds it, only the terminal client followed and a remote one refused, the snapshot read, a socket round trip, a process's path, arguments and variables; `the_foreground_is_the_program_s_own_group`; on X11 with herdr 0.9.5 run in the session: its start showed the focused pane's folder, a cd in the pane moved the panel, the focus moved to a pane in `/etc` and back moved it each time, and the client's end gave the panel back to bash's report; on macOS under `shot`, herdr 0.9.5 as the program, its pane's cd moved the panel | Pass |
 | Colors, styles, five underlines, wide characters, combining marks | T06 | `term::frame`, `term::ink`, `term::paint` tests | Pass |
 | Box drawing, blocks and powerline shapes as geometry | T07 | `term::boxes` tests | Pass |
 | JetBrains Mono, any installed font, Nerd Font icons | T06, T17 | `tests/fonts.rs` | Pass |