v0.2.0 of crossmint_device_signer

Native device-signer plugin for the Crossmint Flutter SDK — hardware-backed key generation and signing via Secure Enclave (iOS) and Android Keystore. Changelog excerpt: - Breaking (native): the iOS deployment target is raised from 13 to 15, and the plugin now declares a required CrossmintDeviceSigner(~> 0.11) CocoaPods dependency. The Dart public API is unchanged. - Native plugins consolidated: the Android (Kotlin) and iOS (Swift) implementations were rewritten to delegate to the shared CrossmintDeviceSignernative packages — the same native code the React Native SDK depends on — for cross-SDK parity. - Native review fixes: Android key operations run o[...]