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>

.gitignore

@@ -0,0 +1,19 @@
+*.iml
+.gradle
+.kotlin
+/local.properties
+/.idea
+.DS_Store
+/build
+/app/build
+/captures
+.externalNativeBuild
+.cxx
+local.properties
+
+# Release keystore — keep safe, don't lose!
+# Uncomment if you want to exclude from repo:
+# release-keystore.jks
+
+# Google services config
+# app/google-services.json