Confirm power and logout actions in centered system modals

docs/backlog.md

@@ -0,0 +1,5 @@
+# Backlog
+
+- [ ] Keep overview open when selecting a workspace and show all of that workspace’s windows. Activate a window only after the user selects it.
+
+- [ ] Add a first-run keybinding guide modal showing important keybindings and their functions. Keep showing it until the user disables the guide in Settings.

docs/configuration.md

@@ -454,3 +454,5 @@ Settings → Windows. `theme.geometry.shell_radius` takes precedence over the ol
 `appearance.corner_radius` and then `theme.geometry.top_bar_radius` keys; when
 none are set, the shell uses 14 px. Legacy clock/note radius fields no longer
 override shell rounding.
+
+Power actions use a centered system confirmation. The `exit` key binding (Super+Shift+E by default) requests logout confirmation; `feresectl request-logout` does the same. `feresectl exit` remains an immediate administrative exit.