Cleaned up ColorSchemeTab, added program checks, added firefox template

Matugen: added firefox (pywalfox) template
SidePanelToggle: use ProgramCheckerService for gpu-screen-recorder
ColorSchemeTab: use NCollapsible for matugen templates, use
ProgramCheckerService to detect available programs (for matugen
templates)
NCollapsible: create collapsible category

Services/ScreenRecorderService.qml

@@ -13,16 +13,13 @@ Singleton {
   property bool isRecording: false
   property bool isPending: false
   property string outputPath: ""
-  property bool isAvailable: false
+  property bool isAvailable: ProgramCheckerService.gpuScreenRecorderAvailable
 
-  Component.onCompleted: {
-    checkAvailability()
-  }
-
-  function checkAvailability() {
-    // Detect native or Flatpak gpu-screen-recorder
-    availabilityCheckProcess.command = ["sh", "-c", "command -v gpu-screen-recorder >/dev/null 2>&1 || (command -v flatpak >/dev/null 2>&1 && flatpak list --app | grep -q 'com.dec05eba.gpu_screen_recorder')"]
-    availabilityCheckProcess.running = true
+  // Update availability when ProgramCheckerService completes its checks
+  Connections {
+    target: ProgramCheckerService
+    function onChecksCompleted() {// Availability is now automatically updated via property binding
+    }
   }
 
   // Start or Stop recording
@@ -101,18 +98,6 @@ Singleton {
     }
   }
 
-  // Availability check process
-  Process {
-    id: availabilityCheckProcess
-    command: ["sh", "-c", "true"]
-    onExited: function (exitCode, exitStatus) {
-      // exitCode 0 means available, non-zero means unavailable
-      root.isAvailable = (exitCode === 0)
-    }
-    stdout: StdioCollector {}
-    stderr: StdioCollector {}
-  }
-
   Timer {
     id: pendingTimer
     interval: 2000 // Wait 2 seconds to see if process stays alive