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/google-services.json

@@ -0,0 +1,29 @@
+{
+  "project_info": {
+    "project_number": "368687825001",
+    "project_id": "bitrix24-contactsyn",
+    "storage_bucket": "bitrix24-contactsyn.firebasestorage.app"
+  },
+  "client": [
+    {
+      "client_info": {
+        "mobilesdk_app_id": "1:368687825001:android:8e744a81d541706c1322f8",
+        "android_client_info": {
+          "package_name": "com.bitrix24.contactsync"
+        }
+      },
+      "oauth_client": [],
+      "api_key": [
+        {
+          "current_key": "AIzaSyCgC4KcfsTx9SqZTw0djr8xDn27dJRWXTw"
+        }
+      ],
+      "services": {
+        "appinvite_service": {
+          "other_platform_oauth_client": []
+        }
+      }
+    }
+  ],
+  "configuration_version": "1"
+}