refactor(performance): Make AppViewHolder a static nested class

The `AppViewHolder` in `FavoriteAdapter` has been converted from an `inner` class to a static nested class. This is a performance optimization that prevents the `AppViewHolder` from holding an implicit reference to the outer `FavoriteAdapter` instance, reducing potential memory leaks.

Additionally, a minor refinement has been made in `HomeFragment`:
- A placeholder text "Select an app" is now displayed for newly added home screen app slots until an app is chosen.
- The inflated `TextView` has been renamed from `view` to the more descriptive `homeAppLabel` for better code clarity.

Author: CreativeCodeCat

app/src/main/java/com/github/droidworksstudio/mlauncher/ui/HomeFragment.kt

@@ -987,11 +987,15 @@ class HomeFragment : BaseFragment(), View.OnClickListener, View.OnLongClickListe
         if (diff > 0) {
             // Add new apps
             for (i in oldAppsNum until newAppsNum) {
-                val view = layoutInflater.inflate(R.layout.home_app_button, null) as TextView
-                view.apply {
+                val homeAppLabel = layoutInflater.inflate(R.layout.home_app_button, null) as TextView
+                homeAppLabel.apply {
                     textSize = prefs.appSize.toFloat()
                     id = i
-                    text = prefs.getHomeAppModel(i).activityLabel
+                    text = if (prefs.getHomeAppModel(i).activityPackage.isBlank()) {
+                        getLocalizedString(R.string.select_app)
+                    } else {
+                        prefs.getHomeAppModel(i).activityLabel
+                    }
                     getHomeAppsGestureListener()
                     setOnClickListener(this@HomeFragment)
 
@@ -1140,7 +1144,7 @@ class HomeFragment : BaseFragment(), View.OnClickListener, View.OnLongClickListe
                     }
                 }
                 // Add the view to the layout
-                binding.homeAppsLayout.addView(view)
+                binding.homeAppsLayout.addView(homeAppLabel)
             }
         } else if (diff < 0) {
             // Remove extra apps

app/src/main/java/com/github/droidworksstudio/mlauncher/ui/adapter/FavoriteAdapter.kt

@@ -22,7 +22,7 @@ class FavoriteAdapter(
     private val prefs: Prefs
 ) : RecyclerView.Adapter<FavoriteAdapter.AppViewHolder>() {
 
-    inner class AppViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
+    class AppViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
         val appTextView: TextView = itemView.findViewById(R.id.homeAppLabel)
     }