Support UI selection via --wpf command-line argument

Refactored Program.cs to accept command-line arguments and select between WinForms (default) and WPF UI based on the presence of --wpf. Removed old commented-out UI selection code. Updated launchSettings.json to provide separate profiles for WinForms and WPF launches. If WPF is requested but unavailable, the app falls back to WinForms.

imagecatalog/Properties/launchSettings.json

@@ -1,7 +1,12 @@
 {
   "profiles": {
-    "Profile 1": {
-      "commandName": "Project"
+    "ImageCatalog (WinForms)": {
+      "commandName": "Project",
+      "commandLineArgs": ""
+    },
+    "ImageCatalog (WPF)": {
+      "commandName": "Project",
+      "commandLineArgs": "--wpf"
     }
   }
-}
+}