T40: sessions post system notifications through gpui's: each terminal posts its own in the order its output asks, when its row turns to waiting, done or error, when a command ends, and when a program asks through OSC 9, 777 or 99, only while its window is inactive or it is hidden, one every 3 seconds, titled with the session's name; a press goes to the window whose session posted it and shows it; OSC 99 hears untracked closes, alive lists what lives, in order before a later DA1, a close and w take one back where gpui can, a closed session's too, and the query says what holds where

README.md

@@ -44,6 +44,7 @@ The app writes its log to stderr. `RUST_LOG=elyterminal=debug` writes more; `tra
 - The terminal runs on `alacritty_terminal`: 256 colors and truecolor, bold, dim, italic, five underline styles, wide characters and combining marks. Box drawing, block elements and powerline shapes are drawn as geometry, so lines join across cells. Keys follow xterm and the kitty keyboard protocol; input methods compose at the cursor; programs can track the mouse; pastes are bracketed when a program asks; OSC 8 and plain links open with the link press below; find searches the scrollback.
 - Shell integration for zsh, bash, fish and PowerShell: each prompt reports its folder and title, and OSC 133 marks each prompt, each command and its exit status.
 - Sessions: new, close and switch. A bell marks a hidden session's row and makes no sound. A row's mark shows what its programs report through OSC 7501, OSC 9;4 or herdr: waiting on you, an error, work with its progress, done or idle, else a failed last command; hover over the mark lists each report.
+- Notifications: while the window is in the background or the session hidden, a session that starts waiting, finishes or fails, and a program's OSC 9, 777 or 99, post a system notification, one a session every 3 seconds at most; a press shows the session. On macOS only the app bundle posts them, not `cargo run`.
 - Cmd-Up and Cmd-Down, Ctrl-Shift-Up and Ctrl-Shift-Down off macOS, jump to the prompt before or after the view's top.
 - A button at each end of the title bar hides or shows its side column, and a drag on the border between a side column and the terminal resizes it; the window opens as it was left, at the size and widths it was left at. On Windows and Linux a gear beside the right one opens Settings.
 - Files shows the session's folder as a tree with Git's marks. Inside herdr the folder is that of herdr's focused pane.