feat: Implement avatar management system with P2P delivery

- Added AvatarRepository for handling avatar storage, retrieval, and delivery.
- Created AvatarCacheEntity and AvatarDeliveryEntity for database storage.
- Introduced PacketAvatar for P2P avatar transfer between clients.
- Enhanced RosettaDatabase to include avatar-related tables and migration.
- Developed AvatarFileManager for file operations related to avatars.
- Implemented AvatarImage composable for displaying user avatars.
- Updated ProfileScreen to support avatar selection and updating.
- Added functionality for handling incoming avatar packets in ProtocolManager.

app/src/main/java/com/rosetta/messenger/database/RosettaDatabase.kt

@@ -12,9 +12,11 @@ import androidx.sqlite.db.SupportSQLiteDatabase
         EncryptedAccountEntity::class,
         MessageEntity::class,
         DialogEntity::class,
-        BlacklistEntity::class
+        BlacklistEntity::class,
+        AvatarCacheEntity::class,
+        AvatarDeliveryEntity::class
     ],
-    version = 6,
+    version = 7,
     exportSchema = false
 )
 abstract class RosettaDatabase : RoomDatabase() {
@@ -22,6 +24,7 @@ abstract class RosettaDatabase : RoomDatabase() {
     abstract fun messageDao(): MessageDao
     abstract fun dialogDao(): DialogDao
     abstract fun blacklistDao(): BlacklistDao
+    abstract fun avatarDao(): AvatarDao
 
     companion object {
         @Volatile
@@ -42,6 +45,31 @@ abstract class RosettaDatabase : RoomDatabase() {
                 database.execSQL("ALTER TABLE encrypted_accounts ADD COLUMN username TEXT")
             }
         }
+        
+        private val MIGRATION_6_7 = object : Migration(6, 7) {
+            override fun migrate(database: SupportSQLiteDatabase) {
+                // Создаем таблицу для кэша аватаров
+                database.execSQL("""
+                    CREATE TABLE IF NOT EXISTS avatar_cache (
+                        id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+                        public_key TEXT NOT NULL,
+                        avatar TEXT NOT NULL,
+                        timestamp INTEGER NOT NULL
+                    )
+                """)
+                database.execSQL("CREATE INDEX IF NOT EXISTS index_avatar_cache_public_key_timestamp ON avatar_cache (public_key, timestamp)")
+                
+                // Создаем таблицу для трекинга доставки аватаров
+                database.execSQL("""
+                    CREATE TABLE IF NOT EXISTS avatar_delivery (
+                        id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL,
+                        public_key TEXT NOT NULL,
+                        account TEXT NOT NULL
+                    )
+                """)
+                database.execSQL("CREATE UNIQUE INDEX IF NOT EXISTS index_avatar_delivery_public_key_account ON avatar_delivery (public_key, account)")
+            }
+        }
 
         fun getDatabase(context: Context): RosettaDatabase {
             return INSTANCE ?: synchronized(this) {
@@ -51,7 +79,7 @@ abstract class RosettaDatabase : RoomDatabase() {
                     "rosetta_secure.db"
                 )
                     .setJournalMode(JournalMode.WRITE_AHEAD_LOGGING) // WAL mode for performance
-                    .addMigrations(MIGRATION_4_5, MIGRATION_5_6)
+                    .addMigrations(MIGRATION_4_5, MIGRATION_5_6, MIGRATION_6_7)
                     .fallbackToDestructiveMigration() // Для разработки - только если миграция не найдена
                     .build()
                 INSTANCE = instance