refactor: separate subscriptions from customer cache

- Split subscription data into separate cache keys for better performance
- Updated cache utilities to handle subscriptions independently
- Modified Lua scripts to manage separate subscription cache entries
- Updated API models and expand logic for separated subscriptions
- Fixed test utilities to match new data structure

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

shared/api/entities/changes/V1.2_EntityChange.ts

@@ -62,6 +62,22 @@ export const V1_2_EntityChange = defineVersionChange({
 				)
 			: undefined;
 
+		const scheduledCusProducts: ApiCusProductV3[] | undefined =
+			input.scheduled_subscriptions
+				? input.scheduled_subscriptions.map((subscription: ApiSubscription) =>
+						transformSubscriptionToCusProductV3({
+							input: subscription,
+							legacyData:
+								legacyData?.cusProductLegacyData[subscription.plan_id],
+						}),
+					)
+				: undefined;
+
+		const finalCusProducts = [
+			...(v0CusProducts || []),
+			...(scheduledCusProducts || []),
+		];
+
 		// Step 2: Transform features V1 → V0
 		let v0_features: Record<string, ApiCusFeatureV3> | undefined;
 		if (input.balances) {
@@ -83,7 +99,7 @@ export const V1_2_EntityChange = defineVersionChange({
 			feature_id: input.feature_id,
 			created_at: input.created_at,
 			env: input.env,
-			products: v0CusProducts,
+			products: finalCusProducts,
 			features: v0_features,
 			invoices:
 				input.invoices?.map((invoice: ApiInvoiceV1) =>