in_app_purchase_watchos 0.0.1

watchOS implementation of the in_app_purchase plugin, using dart:ffi over StoreKit to query products and run purchases through SKPaymentQueue.

0.0.1

• Initial watchOS FFI implementation, started from a flutter-watchos plugin port scaffold of in_app_purchase_storekit.
• Works as a normal federated implementation: apps just add this package and use the standard in_app_purchase API. registerWith() pre-empts the app-facing package's defaultTargetPlatform-based selection, which would otherwise install the iOS method-channel implementation over this one.
• purchaseStream only polls StoreKit while it has a listener, and always cancels its timer — polling with nobody listening costs watch battery.
• buyConsumable asserts autoConsume, matching iOS, instead of silently ignoring it.
• Losing the registration race is now reported via debugPrint rather than failing silently later with an opaque channel-error.
• isAvailable: SKPaymentQueue canMakePayments — the first call every app makes.
• queryProductDetails: StoreKit product lookup (SKProductsRequest) exposed over dart:ffi via a start/poll/read/release handle protocol.
• Purchase flow: buyConsumable / buyNonConsumable, purchaseStream, completePurchase, and restorePurchases via an SKPaymentQueue transaction observer, drained into purchaseStream over dart:ffi.
• Upstream in_app_purchase example (demo UI + official integration_test/) ported to watchOS; builds and passes on the watch simulator.