Added a hopeful quit blocking dialog.

README.md

@@ -440,6 +440,33 @@ GPU. Here, each frame walks the visible rows, groups cells into runs of
 identical style, and hands each run to Pango. That is far more work per frame
 in principle, but a terminal grid is small.
 
+## Quitting
+
+Closing the window asks first, and does so by default. A window here is not one
+shell but a whole arrangement of them, and under a tiling compositor the binding
+that closes it sits a modifier away from the ones that move focus — so there is
+otherwise nothing between a mistyped chord and every shell in every tab exiting.
+The dialog names how many tabs are about to go, which is also the quickest way
+to notice you are about to close the wrong window.
+
+**Keep Working** is the default response, and Escape lands on it too: the guard
+should not itself be a keystroke to fumble. Pressing the compositor's close
+binding again while the question is up dismisses it, which counts as cancelling
+— leaning on the key never costs the window.
+
+Two closes don't ask, because both are already an answer: accepting the dialog,
+and closing the last tab, which is a decision to close the window made one tab
+at a time.
+
+**Settings → Quitting** turns the confirmation off, which puts the window back
+to closing the moment the window manager says so:
+
+```json
+{
+  "confirm_quit": false
+}
+```
+
 ## What works
 
 - Your login shell (from the passwd database, not `$SHELL`) on a real PTY,
@@ -497,6 +524,10 @@ in principle, but a terminal grid is small.
   to the pane in that direction, `Alt+Shift+J/K` steps through tabs. Every chord
   in the app can be rebound in `settings.json`. See
   [Rebinding a shortcut](#rebinding-a-shortcut)
+- **A confirmation before the window closes**, on by default, naming how many
+  tabs would go with it — so a window-manager close binding can't end a session
+  by accident. Switchable from **Settings → Quitting**. See
+  [Quitting](#quitting)
 - **Light and dark schemes**, following the desktop by default and pinnable
   from the settings page, applying to open tabs immediately — terminal palette
   included. See [Theme](#theme)
@@ -1009,6 +1040,7 @@ The preference lives in `~/.config/playpen/settings.json` (or
 {
   "version": 1,
   "theme": "system",
+  "confirm_quit": true,
   "colors": {},
   "startup": []
 }