feat: Implement Dank Launcher button on the Dock

- Configurable with custom icons/logos
- Respects light/dark theme
- Drag & Drop in place

quickshell/Common/SessionData.qml

@@ -83,6 +83,7 @@ Singleton {
     property string nightModeLocationProvider: ""
 
     property var pinnedApps: []
+    property int dockLauncherPosition: 0
     property var hiddenTrayIds: []
     property var recentColors: []
     property bool showThirdPartyPlugins: false

quickshell/Common/SettingsData.qml

@@ -431,6 +431,13 @@ Singleton {
     property real dockBorderOpacity: 1.0
     property int dockBorderThickness: 1
     property bool dockIsolateDisplays: false
+    property bool dockLauncherEnabled: false
+    property string dockLauncherLogoMode: "apps"
+    property string dockLauncherLogoCustomPath: ""
+    property string dockLauncherLogoColorOverride: ""
+    property int dockLauncherLogoSizeOffset: 0
+    property real dockLauncherLogoBrightness: 0.5
+    property real dockLauncherLogoContrast: 1
 
     property bool notificationOverlayEnabled: false
     property int overviewRows: 2

quickshell/Common/settings/SettingsSpec.js

@@ -255,6 +255,13 @@ var SPEC = {
     dockBorderOpacity: { def: 1.0, coerce: percentToUnit },
     dockBorderThickness: { def: 1 },
     dockIsolateDisplays: { def: false },
+    dockLauncherEnabled: { def: false },
+    dockLauncherLogoMode: { def: "apps" },
+    dockLauncherLogoCustomPath: { def: "" },
+    dockLauncherLogoColorOverride: { def: "" },
+    dockLauncherLogoSizeOffset: { def: 0 },
+    dockLauncherLogoBrightness: { def: 0.5, coerce: percentToUnit },
+    dockLauncherLogoContrast: { def: 1, coerce: percentToUnit },
 
     notificationOverlayEnabled: { def: false },
     overviewRows: { def: 2, persist: false },