feat: Implement setup screen and login logic

- Add SetupScreen with UI for server URL, username, and password input.
- Make SetupScreen the initial screen in the navigation graph.
- Implement secure credential storage using EncryptedSharedPreferences.
- Create CredentialsRepository and AuthRepository to manage credentials and auth tokens.
- Add LoginUseCase to handle the business logic for logging in.
- Implement a temporary Retrofit client in ItemRepository to handle login against a user-provided URL.
- Integrate login logic into SetupViewModel.
- Update all relevant project documentation and DI modules.

data/src/main/java/com/homebox/lens/data/api/HomeboxApiService.kt

@@ -10,7 +10,9 @@ import com.homebox.lens.data.api.dto.ItemSummaryDto
 import com.homebox.lens.data.api.dto.ItemUpdateDto
 import com.homebox.lens.data.api.dto.LabelOutDto
 import com.homebox.lens.data.api.dto.LocationOutCountDto
+import com.homebox.lens.data.api.dto.LoginFormDto
 import com.homebox.lens.data.api.dto.PaginationResultDto
+import com.homebox.lens.data.api.dto.TokenResponseDto
 import retrofit2.Response
 import retrofit2.http.Body
 import retrofit2.http.DELETE
@@ -27,6 +29,10 @@ import retrofit2.http.Query
  */
 interface HomeboxApiService {
 
+    // [ENDPOINT] Auth
+    @POST("v1/users/login")
+    suspend fun login(@Body loginForm: LoginFormDto): TokenResponseDto
+
     // [ENDPOINT] Items
     @GET("v1/items")
     suspend fun getItems(

data/src/main/java/com/homebox/lens/data/api/dto/LoginFormDto.kt

@@ -0,0 +1,15 @@
+// [PACKAGE] com.homebox.lens.data.api.dto
+// [FILE] LoginFormDto.kt
+
+package com.homebox.lens.data.api.dto
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+data class LoginFormDto(
+    @Json(name = "username") val username: String,
+    @Json(name = "password") val password: String,
+    @Json(name = "stayLoggedIn") val stayLoggedIn: Boolean = true
+)
+// [END_FILE_LoginFormDto.kt]

data/src/main/java/com/homebox/lens/data/api/dto/TokenResponseDto.kt

@@ -0,0 +1,15 @@
+// [PACKAGE] com.homebox.lens.data.api.dto
+// [FILE] TokenResponseDto.kt
+
+package com.homebox.lens.data.api.dto
+
+import com.squareup.moshi.Json
+import com.squareup.moshi.JsonClass
+
+@JsonClass(generateAdapter = true)
+data class TokenResponseDto(
+    @Json(name = "token") val token: String,
+    @Json(name = "attachmentToken") val attachmentToken: String,
+    @Json(name = "expiresAt") val expiresAt: String
+)
+// [END_FILE_TokenResponseDto.kt]

data/src/main/java/com/homebox/lens/data/di/ApiModule.kt

@@ -56,12 +56,19 @@ object ApiModule {
     // [PROVIDER]
     @Provides
     @Singleton
-    fun provideRetrofit(okHttpClient: OkHttpClient, moshi: Moshi): Retrofit {
+    fun provideMoshiConverterFactory(moshi: Moshi): MoshiConverterFactory {
+        return MoshiConverterFactory.create(moshi)
+    }
+
+    // [PROVIDER]
+    @Provides
+    @Singleton
+    fun provideRetrofit(okHttpClient: OkHttpClient, moshiConverterFactory: MoshiConverterFactory): Retrofit {
         // [ACTION] Build Retrofit instance
         return Retrofit.Builder()
             .baseUrl(BASE_URL)
             .client(okHttpClient)
-            .addConverterFactory(MoshiConverterFactory.create(moshi))
+            .addConverterFactory(moshiConverterFactory)
             .build()
     }
 

data/src/main/java/com/homebox/lens/data/di/RepositoryModule.kt

@@ -3,11 +3,13 @@
 
 package com.homebox.lens.data.di
 
-import com.homebox.lens.data.api.HomeboxApiService
-import com.homebox.lens.data.repository.ItemRepositoryImpl
+import com.homebox.lens.data.repository.AuthRepositoryImpl
+import com.homebox.lens.data.repository.CredentialsRepositoryImpl
+import com.homebox.lens.domain.repository.AuthRepository
+import com.homebox.lens.domain.repository.CredentialsRepository
 import com.homebox.lens.domain.repository.ItemRepository
+import dagger.Binds
 import dagger.Module
-import dagger.Provides
 import dagger.hilt.InstallIn
 import dagger.hilt.components.SingletonComponent
 import javax.inject.Singleton
@@ -15,18 +17,23 @@ import javax.inject.Singleton
 // [CONTRACT]
 /**
  * [MODULE: DaggerHilt('RepositoryModule')]
- * [PURPOSE] Предоставляет реализацию для интерфейса ItemRepository.
+ * [PURPOSE] Предоставляет реализации для интерфейсов репозиториев.
  */
 @Module
 @InstallIn(SingletonComponent::class)
-object RepositoryModule {
+abstract class RepositoryModule {
 
-    // [PROVIDER]
-    @Provides
+    @Binds
     @Singleton
-    fun provideItemRepository(apiService: HomeboxApiService): ItemRepository {
-        return ItemRepositoryImpl(apiService)
-    }
+    abstract fun bindItemRepository(itemRepositoryImpl: com.homebox.lens.data.repository.ItemRepositoryImpl): ItemRepository
+
+    @Binds
+    @Singleton
+    abstract fun bindCredentialsRepository(credentialsRepositoryImpl: CredentialsRepositoryImpl): CredentialsRepository
+
+    @Binds
+    @Singleton
+    abstract fun bindAuthRepository(authRepositoryImpl: AuthRepositoryImpl): AuthRepository
 }
 
 // [END_FILE_RepositoryModule.kt]

data/src/main/java/com/homebox/lens/data/di/StorageModule.kt

@@ -0,0 +1,37 @@
+// [PACKAGE] com.homebox.lens.data.di
+// [FILE] StorageModule.kt
+
+package com.homebox.lens.data.di
+
+import android.content.Context
+import android.content.SharedPreferences
+import androidx.security.crypto.EncryptedSharedPreferences
+import androidx.security.crypto.MasterKey
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.components.SingletonComponent
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+object StorageModule {
+
+    @Provides
+    @Singleton
+    fun provideEncryptedSharedPreferences(@ApplicationContext context: Context): SharedPreferences {
+        val masterKey = MasterKey.Builder(context)
+            .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
+            .build()
+
+        return EncryptedSharedPreferences.create(
+            context,
+            "secret_shared_prefs",
+            masterKey,
+            EncryptedSharedPreferences.PrefKeyEncryptionScheme.AES256_SIV,
+            EncryptedSharedPreferences.PrefValueEncryptionScheme.AES256_GCM
+        )
+    }
+}
+// [END_FILE_StorageModule.kt]

data/src/main/java/com/homebox/lens/data/repository/AuthRepositoryImpl.kt

@@ -0,0 +1,30 @@
+// [PACKAGE] com.homebox.lens.data.repository
+// [FILE] AuthRepositoryImpl.kt
+
+package com.homebox.lens.data.repository
+
+import android.content.SharedPreferences
+import com.homebox.lens.domain.repository.AuthRepository
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import javax.inject.Inject
+
+class AuthRepositoryImpl @Inject constructor(
+    private val encryptedPrefs: SharedPreferences
+) : AuthRepository {
+
+    companion object {
+        private const val KEY_AUTH_TOKEN = "key_auth_token"
+    }
+
+    override suspend fun saveToken(token: String) {
+        encryptedPrefs.edit().putString(KEY_AUTH_TOKEN, token).apply()
+    }
+
+    override fun getToken(): Flow<String?> = flow {
+        emit(encryptedPrefs.getString(KEY_AUTH_TOKEN, null))
+    }.flowOn(Dispatchers.IO)
+}
+// [END_FILE_AuthRepositoryImpl.kt]

data/src/main/java/com/homebox/lens/data/repository/CredentialsRepositoryImpl.kt

@@ -0,0 +1,46 @@
+// [PACKAGE] com.homebox.lens.data.repository
+// [FILE] CredentialsRepositoryImpl.kt
+
+package com.homebox.lens.data.repository
+
+import android.content.SharedPreferences
+import com.homebox.lens.domain.model.Credentials
+import com.homebox.lens.domain.repository.CredentialsRepository
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
+import javax.inject.Inject
+
+// [REPOSITORY_IMPL]
+class CredentialsRepositoryImpl @Inject constructor(
+    private val encryptedPrefs: SharedPreferences
+) : CredentialsRepository {
+
+    companion object {
+        private const val KEY_SERVER_URL = "key_server_url"
+        private const val KEY_USERNAME = "key_username"
+        private const val KEY_PASSWORD = "key_password"
+    }
+
+    override suspend fun saveCredentials(credentials: Credentials) {
+        encryptedPrefs.edit()
+            .putString(KEY_SERVER_URL, credentials.serverUrl)
+            .putString(KEY_USERNAME, credentials.username)
+            .putString(KEY_PASSWORD, credentials.password)
+            .apply()
+    }
+
+    override fun getCredentials(): Flow<Credentials?> = flow {
+        val serverUrl = encryptedPrefs.getString(KEY_SERVER_URL, null)
+        val username = encryptedPrefs.getString(KEY_USERNAME, null)
+        val password = encryptedPrefs.getString(KEY_PASSWORD, null)
+
+        if (serverUrl != null && username != null && password != null) {
+            emit(Credentials(serverUrl, username, password))
+        } else {
+            emit(null)
+        }
+    }.flowOn(Dispatchers.IO)
+}
+// [END_FILE_CredentialsRepositoryImpl.kt]

data/src/main/java/com/homebox/lens/data/repository/ItemRepositoryImpl.kt

@@ -4,10 +4,15 @@
 package com.homebox.lens.data.repository
 // [IMPORTS]
 import com.homebox.lens.data.api.HomeboxApiService
+import com.homebox.lens.data.api.dto.LoginFormDto
 import com.homebox.lens.data.api.dto.toDomain
 import com.homebox.lens.data.api.dto.toDto
 import com.homebox.lens.domain.model.*
+import com.homebox.lens.domain.repository.AuthRepository
 import com.homebox.lens.domain.repository.ItemRepository
+import okhttp3.OkHttpClient
+import retrofit2.Retrofit
+import retrofit2.converter.moshi.MoshiConverterFactory
 import javax.inject.Inject
 import javax.inject.Singleton
 
@@ -19,9 +24,29 @@ import javax.inject.Singleton
  */
 @Singleton
 class ItemRepositoryImpl @Inject constructor(
-    private val apiService: HomeboxApiService
+    private val apiService: HomeboxApiService,
+    private val authRepository: AuthRepository,
+    private val okHttpClient: OkHttpClient,
+    private val moshiConverterFactory: MoshiConverterFactory
 ) : ItemRepository {
 
+    override suspend fun login(credentials: Credentials): Result<Unit> {
+        return try {
+            val tempApiService = Retrofit.Builder()
+                .baseUrl(credentials.serverUrl)
+                .client(okHttpClient)
+                .addConverterFactory(moshiConverterFactory)
+                .build()
+                .create(HomeboxApiService::class.java)
+
+            val loginForm = LoginFormDto(credentials.username, credentials.password)
+            val tokenResponse = tempApiService.login(loginForm)
+            authRepository.saveToken(tokenResponse.token)
+            Result.Success(Unit)
+        } catch (e: Exception) {
+            Result.Error(e)
+        }
+    }
     /**
      * [CONTRACT] @see ItemRepository.createItem
      */