feat: support Capacitor 6 & 7

Widen the @capacitor/core peer range to >=5.0.0 <8.0.0 (adds v6 and v7
alongside existing v5) and move the build toolchain to Capacitor 7 levels:

- peerDependencies @capacitor/core: ^5.0.0 -> >=5.0.0 <8.0.0
- devDependencies @capacitor/{core,android,ios}: ^5.0.0 -> ^7.0.0
- Android: AGP 8.6.0 -> 8.7.2, Gradle 8.4 -> 8.11.1, compileSdk/targetSdk 34 -> 35
- Fix addListener() for Capacitor 6+: drop the legacy
  '& PluginListenerHandle' intersection from the return type
- Bump version 2.1.0 -> 2.2.0

iOS deployment target (14) and minSdk (26) already satisfy Capacitor 7.
TS/JS build verified against @capacitor/core 7.6.7. Supersedes #51.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: dianaKhortiuk-frontegg

android/build.gradle

@@ -11,18 +11,18 @@ buildscript {
         mavenCentral()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:8.6.0'
+        classpath 'com.android.tools.build:gradle:8.7.2'
     }
 }
 
 apply plugin: 'com.android.library'
 
 android {
     namespace "com.frontegg.ionic"
-    compileSdkVersion project.hasProperty('compileSdkVersion') ? rootProject.ext.compileSdkVersion : 34
+    compileSdkVersion project.hasProperty('compileSdkVersion') ? rootProject.ext.compileSdkVersion : 35
     defaultConfig {
         minSdkVersion project.hasProperty('minSdkVersion') ? rootProject.ext.minSdkVersion : 26
-        targetSdkVersion project.hasProperty('targetSdkVersion') ? rootProject.ext.targetSdkVersion : 34
+        targetSdkVersion project.hasProperty('targetSdkVersion') ? rootProject.ext.targetSdkVersion : 35
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"

android/gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.4-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.11.1-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists