feat(android): add persistent partyId storage matching Electron behavior

- Add AppSettingEntity and AppSettingDao to Database.kt for key-value storage
- Add database migration (version 1 → 2) to create app_settings table
- Modify TssRepository.registerParty() to load/create partyId from database
- PartyId is now persisted across app restarts, matching Electron's getOrCreatePartyId()

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.claude/settings.local.json

@@ -552,7 +552,8 @@
       "Bash(\"/c/Users/dong/go/bin/go1.22.10.exe\" install golang.org/x/mobile/cmd/gomobile@c31d5b91ecc32c0d598b8fe8457d244ca0b4e815)",
       "Bash(\"/c/Users/dong/go/bin/go1.22.10.exe\" install golang.org/x/mobile/cmd/gobind@c31d5b91ecc32c0d598b8fe8457d244ca0b4e815)",
       "Bash(\"/c/Users/dong/go/bin/go1.22.10.exe\" mod tidy)",
-      "Bash(adb devices:*)"
+      "Bash(adb devices:*)",
+      "Bash(adb logcat:*)"
     ],
     "deny": [],
     "ask": []

backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/data/local/Database.kt

@@ -66,14 +66,39 @@ interface ShareRecordDao {
     suspend fun getShareCount(): Int
 }
 
+/**
+ * Entity for storing app settings (like persistent partyId)
+ */
+@Entity(tableName = "app_settings")
+data class AppSettingEntity(
+    @PrimaryKey
+    val key: String,
+
+    @ColumnInfo(name = "value")
+    val value: String
+)
+
+/**
+ * DAO for app settings
+ */
+@Dao
+interface AppSettingDao {
+    @Query("SELECT value FROM app_settings WHERE `key` = :key")
+    suspend fun getValue(key: String): String?
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    suspend fun setValue(setting: AppSettingEntity)
+}
+
 /**
  * Room database
  */
 @Database(
-    entities = [ShareRecordEntity::class],
+    entities = [ShareRecordEntity::class, AppSettingEntity::class],
-    version = 1,
+    version = 2,
     exportSchema = false
 )
 abstract class TssDatabase : RoomDatabase() {
     abstract fun shareRecordDao(): ShareRecordDao
+    abstract fun appSettingDao(): AppSettingDao
 }

backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/data/repository/TssRepository.kt

@@ -1,6 +1,8 @@
 package com.durian.tssparty.data.repository
 
 import android.util.Base64
+import com.durian.tssparty.data.local.AppSettingDao
+import com.durian.tssparty.data.local.AppSettingEntity
 import com.durian.tssparty.data.local.ShareRecordDao
 import com.durian.tssparty.data.local.ShareRecordEntity
 import com.durian.tssparty.data.local.TssNativeBridge
@@ -28,7 +30,8 @@ import javax.inject.Singleton
 class TssRepository @Inject constructor(
     private val grpcClient: GrpcClient,
     private val tssNativeBridge: TssNativeBridge,
-    private val shareRecordDao: ShareRecordDao
+    private val shareRecordDao: ShareRecordDao,
+    private val appSettingDao: AppSettingDao
 ) {
     private val _currentSession = MutableStateFlow<TssSession?>(null)
     val currentSession: StateFlow<TssSession?> = _currentSession.asStateFlow()
@@ -42,7 +45,9 @@ class TssRepository @Inject constructor(
     // Expose gRPC connection events for UI notifications
     val grpcConnectionEvents: SharedFlow<GrpcConnectionEvent> = grpcClient.connectionEvents
 
-    private var partyId: String = UUID.randomUUID().toString()
+    // partyId is loaded once from database in registerParty() and cached here
+    // This matches Electron's getOrCreatePartyId() pattern
+    private lateinit var partyId: String
     private var messageCollectionJob: Job? = null
     private var sessionEventJob: Job? = null
 
@@ -56,8 +61,14 @@ class TssRepository @Inject constructor(
 
     /**
      * Get the current party ID
+     * Note: This will throw UninitializedPropertyAccessException if called before registerParty()
      */
-    fun getPartyId(): String = partyId
+    fun getPartyId(): String {
+        if (!::partyId.isInitialized) {
+            throw IllegalStateException("partyId not initialized. Call registerParty() first.")
+        }
+        return partyId
+    }
 
     // Track current message routing params for reconnection recovery
     private var currentMessageRoutingSessionId: String? = null
@@ -146,8 +157,23 @@ class TssRepository @Inject constructor(
     /**
      * Register this party with the router
      * Also subscribes to session events (matching Electron behavior)
+     *
+     * This method loads or creates a persistent partyId from the database (matching Electron's
+     * getOrCreatePartyId pattern). The partyId is loaded ONCE here and cached in memory.
      */
     suspend fun registerParty(): String {
+        // Load or create persistent partyId (matching Electron's getOrCreatePartyId)
+        val existingPartyId = appSettingDao.getValue("party_id")
+        partyId = if (existingPartyId != null) {
+            android.util.Log.d("TssRepository", "Loaded existing partyId: $existingPartyId")
+            existingPartyId
+        } else {
+            val newPartyId = UUID.randomUUID().toString()
+            appSettingDao.setValue(AppSettingEntity("party_id", newPartyId))
+            android.util.Log.d("TssRepository", "Generated new partyId: $newPartyId")
+            newPartyId
+        }
+
         grpcClient.registerParty(partyId, "temporary", "1.0.0")
 
         // Subscribe to session events immediately after registration (like Electron does)

backend/mpc-system/services/service-party-android/app/src/main/java/com/durian/tssparty/di/AppModule.kt

@@ -2,6 +2,9 @@ package com.durian.tssparty.di
 
 import android.content.Context
 import androidx.room.Room
+import androidx.room.migration.Migration
+import androidx.sqlite.db.SupportSQLiteDatabase
+import com.durian.tssparty.data.local.AppSettingDao
 import com.durian.tssparty.data.local.ShareRecordDao
 import com.durian.tssparty.data.local.TssDatabase
 import com.durian.tssparty.data.local.TssNativeBridge
@@ -20,6 +23,17 @@ import javax.inject.Singleton
 @InstallIn(SingletonComponent::class)
 object AppModule {
 
+    // Migration from version 1 to 2: add app_settings table
+    private val MIGRATION_1_2 = object : Migration(1, 2) {
+        override fun migrate(database: SupportSQLiteDatabase) {
+            database.execSQL(
+                "CREATE TABLE IF NOT EXISTS `app_settings` (" +
+                "`key` TEXT NOT NULL PRIMARY KEY, " +
+                "`value` TEXT NOT NULL)"
+            )
+        }
+    }
+
     @Provides
     @Singleton
     fun provideGson(): Gson {
@@ -33,7 +47,9 @@ object AppModule {
             context,
             TssDatabase::class.java,
             "tss_party.db"
-        ).build()
+        )
+            .addMigrations(MIGRATION_1_2)
+            .build()
     }
 
     @Provides
@@ -42,6 +58,12 @@ object AppModule {
         return database.shareRecordDao()
     }
 
+    @Provides
+    @Singleton
+    fun provideAppSettingDao(database: TssDatabase): AppSettingDao {
+        return database.appSettingDao()
+    }
+
     @Provides
     @Singleton
     fun provideGrpcClient(): GrpcClient {
@@ -59,8 +81,9 @@ object AppModule {
     fun provideTssRepository(
         grpcClient: GrpcClient,
         tssNativeBridge: TssNativeBridge,
-        shareRecordDao: ShareRecordDao
+        shareRecordDao: ShareRecordDao,
+        appSettingDao: AppSettingDao
     ): TssRepository {
-        return TssRepository(grpcClient, tssNativeBridge, shareRecordDao)
+        return TssRepository(grpcClient, tssNativeBridge, shareRecordDao, appSettingDao)
     }
 }