fix(ci): restore -destination flag for SwiftPM xcodebuild

-sdk alone is rejected; SwiftPM packages require -destination.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

codemagic.yaml

@@ -24,7 +24,7 @@ workflows:
         script: |
           xcodebuild build \
             -scheme SilverApple \
-            -sdk iphoneos \
+            -destination "generic/platform=iOS" \
             -configuration Release \
             -derivedDataPath "$CM_BUILD_DIR/DerivedData" \
             CODE_SIGNING_ALLOWED=NO \