iOS: dev builds get a 'dev ♡' sash on the app icon (AppIconDev)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

ios/project.yml

@@ -13,6 +13,7 @@ settings:
     # Dev builds override these (build-ipa.sh dev) so they install next to the release app.
     APP_ID: org.cdnutter.stemify
     APP_NAME: Stemify
+    APP_ICON: AppIcon
 targets:
   Stemify:
     type: application
@@ -24,7 +25,7 @@ targets:
       base:
         PRODUCT_BUNDLE_IDENTIFIER: $(APP_ID)
         TARGETED_DEVICE_FAMILY: "1"
-        ASSETCATALOG_COMPILER_APPICON_NAME: AppIcon
+        ASSETCATALOG_COMPILER_APPICON_NAME: $(APP_ICON)
         CODE_SIGN_ENTITLEMENTS: Stemify/Stemify.entitlements
     entitlements:
       path: Stemify/Stemify.entitlements