Fix subscription screen hanging on "Loading Subscription"

The .containerRelativeFrame(.horizontal) on the marketing content
caused an infinite layout loop inside SubscriptionStoreView's scroll
container. Replaced with .frame(maxWidth: .infinity).

Also fixes leading space in StoreKit config display name, adds
debug logging to product loading, and reverts to groupID initializer.

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

Configuration.storekit

@@ -56,7 +56,7 @@
           "localizations" : [
             {
               "description" : "Unlock all features with monthly access.",
-              "displayName" : " Reflect Monthly",
+              "displayName" : "Reflect Monthly",
               "locale" : "en_US"
             },
             {