Add NInputButton widget and FileManagerService integration

NInputButton.qml: new input+button widget
FileManagerService.qml: singleton service for file/folder dialogs
NFileManager.qml: create first iteration of filemanager
WallpaperTab.qml: integrate NInputButton
ScreenRecorderTab.qml: integrate NInputButton
GeneralTab.qml: integrate NInputButton

Modules/SettingsPanel/Tabs/GeneralTab.qml

@@ -30,15 +30,30 @@ ColumnLayout {
       Layout.alignment: Qt.AlignTop
     }
 
-    NTextInput {
-      Layout.fillWidth: true
+    NInputButton {
       label: `${Quickshell.env("USER") || "user"}'s profile picture`
       description: "Your profile picture that appears throughout the interface."
       text: Settings.data.general.avatarImage
       placeholderText: "/home/user/.face"
-      onEditingFinished: {
+      buttonIcon: "photo"
+      buttonTooltip: "Browse for avatar image"
+
+      onInputEditingFinished: {
         Settings.data.general.avatarImage = text
       }
+      onButtonClicked: {
+        FileManagerService.open({
+                                  "title": "Select Avatar Image",
+                                  "initialPath": Settings.data.general.avatarImage || Quickshell.env("HOME"),
+                                  "selectFiles": true,
+                                  "scaling": scaling,
+                                  "onSelected": function (path) {
+                                    Settings.data.general.avatarImage = path
+                                    text = path
+                                  },
+                                  "parent": root
+                                })
+      }
     }
   }