v1.0.0 of influto_iap

Automatic store-purchase capture for the InfluTo Flutter SDK: listens to in_app_purchase and reports each purchase to InfluTo, so store-direct apps need no manual reporting. Changelog excerpt: Initial release of influto_iap, the automatic store-purchase capture companion for the influtoFlutter SDK. ### Added - InfluToPurchaseObserver— listens to in_app_purchase's purchaseStreamand auto-reports each new store purchase to InfluTo (StoreKit 2 JWS on iOS, Play purchase token on Android), plus a one-time historical back-sync via enable(). - Self-gates on store-direct apps (no-op for RevenueCat apps), deduped per store identity; the backend [...]