quickshell: caffeine toggle in battery dropdown

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

settings/quickshell.nix

@@ -4666,6 +4666,7 @@ in
                                 let pos = batteryWidget.mapToItem(bar.contentItem, 0, batteryWidget.height / 2);
                                 batteryDropdown.dropdownY = pos.y;
                                 brightRead.running = true;   // refresh sliders on open
+                                caffRead.running = true;     // and the caffeine state
                             });
                         }
 
@@ -6092,6 +6093,56 @@ in
                             }
                         }
 
+
+                        // Caffeine card — parks hypridle so nothing locks,
+                        // blanks or suspends. State is re-read on open, so a
+                        // hypridle restart can't leave the switch lying.
+                        Card {
+                            id: caffCard
+                            width: parent.width
+                            property bool on: false
+
+                            Item {
+                                width: parent.width
+                                height: 20
+                                Row {
+                                    spacing: 6
+                                    anchors.verticalCenter: parent.verticalCenter
+                                    SIcon {
+                                        anchors.verticalCenter: parent.verticalCenter
+                                        text: "coffee"
+                                        color: caffCard.on ? Theme.base0D : Theme.base05
+                                        font.pixelSize: 15
+                                    }
+                                    SText {
+                                        anchors.verticalCenter: parent.verticalCenter
+                                        text: "Caffeine"
+                                        font.weight: Font.Medium
+                                    }
+                                }
+                                ToggleSwitch {
+                                    anchors.right: parent.right
+                                    anchors.verticalCenter: parent.verticalCenter
+                                    on: caffCard.on
+                                    onToggled: (v) => {
+                                        caffCard.on = v;
+                                        caffSet.command = [Commands.systemctl, "--user", v ? "stop" : "start", "hypridle.service"];
+                                        caffSet.running = true;
+                                    }
+                                }
+                            }
+
+                            Process { id: caffSet }
+                            Process {
+                                id: caffRead
+                                command: [Commands.systemctl, "--user", "is-active", "hypridle.service"]
+                                stdout: StdioCollector {
+                                    // is-active exits non-zero when stopped; the
+                                    // word on stdout is what matters here.
+                                    onStreamFinished: caffCard.on = text.trim() !== "active"
+                                }
+                            }
+                        }
                         // Brightness card — screen + keyboard backlight.
                         // Values are read on dropdown open (brightRead); writes
                         // are debounced latest-wins so a drag doesn't spawn a