Initial commit: ContactSync Android app

- SyncAdapter with account type com.bitrix24.contacts.sync
- Two-phase sync: download to Room DB, then import to phone contacts
- FCM push for instant contact addition
- WorkManager: periodic sync (30min) + heartbeat (1h)
- QR code activation (JSON format)
- Event log UI with LiveData
- Auto-update mechanism via version.php
- Duplicate contacts cleanup
- CALLER_IS_SYNCADAPTER optimization for bulk inserts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/build.gradle.kts

@@ -0,0 +1,89 @@
+plugins {
+    alias(libs.plugins.android.application)
+    alias(libs.plugins.kotlin.android)
+    alias(libs.plugins.ksp)
+    alias(libs.plugins.google.services)
+}
+
+android {
+    namespace = "com.bitrix24.contactsync"
+    compileSdk = 34
+
+    defaultConfig {
+        applicationId = "com.bitrix24.contactsync"
+        minSdk = 26
+        targetSdk = 34
+        versionCode = 1
+        versionName = "1.0.0"
+    }
+
+    signingConfigs {
+        create("release") {
+            storeFile = file("../release-keystore.jks")
+            storePassword = "ContactSync2024"
+            keyAlias = "contactsync"
+            keyPassword = "ContactSync2024"
+        }
+    }
+
+    buildTypes {
+        release {
+            isMinifyEnabled = true
+            proguardFiles(
+                getDefaultProguardFile("proguard-android-optimize.txt"),
+                "proguard-rules.pro"
+            )
+            signingConfig = signingConfigs.getByName("release")
+        }
+    }
+
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_17
+        targetCompatibility = JavaVersion.VERSION_17
+    }
+
+    kotlinOptions {
+        jvmTarget = "17"
+    }
+
+    buildFeatures {
+        viewBinding = true
+        buildConfig = true
+    }
+}
+
+dependencies {
+    implementation(libs.androidx.core.ktx)
+    implementation(libs.androidx.appcompat)
+    implementation(libs.androidx.activity.ktx)
+    implementation(libs.material)
+
+    // Room
+    implementation(libs.room.runtime)
+    implementation(libs.room.ktx)
+    ksp(libs.room.compiler)
+
+    // WorkManager
+    implementation(libs.workmanager)
+
+    // Retrofit + OkHttp
+    implementation(libs.retrofit)
+    implementation(libs.retrofit.gson)
+    implementation(libs.okhttp)
+    implementation(libs.okhttp.logging)
+
+    // Firebase
+    implementation(platform(libs.firebase.bom))
+    implementation(libs.firebase.messaging)
+
+    // Lifecycle
+    implementation(libs.lifecycle.runtime)
+    implementation(libs.lifecycle.viewmodel)
+
+    // Coroutines
+    implementation(libs.coroutines.core)
+    implementation(libs.coroutines.android)
+
+    // QR Scanner
+    implementation(libs.zxing)
+}