refactor: unify desktop apps and Settings under item catalog

programs/src/timezone/main.cpp

@@ -1,6 +1,6 @@
 /*
  * main.cpp
- * MontaukOS Time Zone configuration applet
+ * MontaukOS Time Zone configuration app
  * Copyright (c) 2026 Daniel Hammer
  */
 

programs/src/timezone/manifest.toml

@@ -1,4 +1,5 @@
 [app]
+id = "timezone"
 name = "Time Zone"
 binary = "timezone.elf"
 icon = "preferences-system-time.svg"
@@ -6,3 +7,7 @@ icon = "preferences-system-time.svg"
 [menu]
 category = "System"
 visible = false
+
+[desktop]
+section = "settings"
+admin_only = false