feat(characters:data): DTOs, mappers, data source, repo, Koin module (REDI-86)

- @Serializable CharacterDto/CharactersResponseDto/PageInfoDto in dto/.
- mappers/CharacterMapper.kt: internal, pure toDomain()/toCharacter()/toCharacterDetails();
  nextPage parsed from info.next URL. No mapping inside DTO/data-source classes.
- KtorCharacterDataSource via the typed HttpClient.get helpers (errors -> DataError.Network).
- NetworkCharacterRepository (not *Impl) maps DTO -> domain; DataError.Network widens to DataError.
- charactersDataModule: singleOf(::KtorCharacterDataSource) + singleOf(::NetworkCharacterRepository) { bind<CharacterRepository>() }.
- core:data: expose ktor-client-core as api (public inline helpers are inlined into consumers) and
  move Timber logging into a @PublishedApi internal fn so Timber doesn't leak across modules.

core/data/build.gradle.kts

@@ -19,4 +19,7 @@ android {
 dependencies {
     implementation(project(":core:domain"))
     implementation(libs.timber)
+    // `api`: the public inline HttpClient.get/post/delete helpers are inlined into consumer modules,
+    // so those modules need the Ktor request/response types on their compile classpath.
+    api(libs.ktor.client.core)
 }

core/data/src/main/kotlin/com/example/architecture/core/data/network/HttpClientExt.kt

@@ -65,21 +65,31 @@ suspend inline fun <reified T> safeCall(
     return try {
         responseToResult(execute())
     } catch (e: UnresolvedAddressException) {
-        Timber.tag("HttpClient").e(e, "No internet (unresolved address)")
+        logNetworkError(e, "No internet (unresolved address)")
         Result.Error(DataError.Network.NO_INTERNET)
     } catch (e: UnknownHostException) {
-        Timber.tag("HttpClient").e(e, "No internet (unknown host)")
+        logNetworkError(e, "No internet (unknown host)")
         Result.Error(DataError.Network.NO_INTERNET)
     } catch (e: SerializationException) {
-        Timber.tag("HttpClient").e(e, "Serialization failure")
+        logNetworkError(e, "Serialization failure")
         Result.Error(DataError.Network.SERIALIZATION)
     } catch (e: Exception) {
         if (e is CancellationException) throw e
-        Timber.tag("HttpClient").e(e, "Unknown network failure")
+        logNetworkError(e, "Unknown network failure")
         Result.Error(DataError.Network.UNKNOWN)
     }
 }
 
+/**
+ * Logs a caught network error. `@PublishedApi internal` so the public inline [safeCall] can call it
+ * across modules WITHOUT leaking Timber: the Timber dependency stays inside `:core:data` because
+ * this function's body is not inlined into the caller.
+ */
+@PublishedApi
+internal fun logNetworkError(throwable: Throwable, message: String) {
+    Timber.tag("HttpClient").e(throwable, message)
+}
+
 /** Maps HTTP status codes to typed [DataError.Network] (extends the skill table with 400/403/404). */
 suspend inline fun <reified T> responseToResult(
     response: HttpResponse,

feature/characters/data/src/main/kotlin/com/example/architecture/feature/characters/data/NetworkCharacterRepository.kt

@@ -0,0 +1,25 @@
+package com.example.architecture.feature.characters.data
+
+import com.example.architecture.core.domain.DataError
+import com.example.architecture.core.domain.Result
+import com.example.architecture.core.domain.map
+import com.example.architecture.feature.characters.data.datasource.KtorCharacterDataSource
+import com.example.architecture.feature.characters.data.mappers.toCharacterDetails
+import com.example.architecture.feature.characters.data.mappers.toDomain
+import com.example.architecture.feature.characters.domain.CharacterRepository
+import com.example.architecture.feature.characters.domain.model.CharacterDetails
+import com.example.architecture.feature.characters.domain.model.CharactersPage
+
+/**
+ * Network-backed [CharacterRepository]. Maps DTOs to domain via the mappers; the `Result`'s
+ * `DataError.Network` widens to the `DataError` supertype through `Result`'s covariance.
+ */
+internal class NetworkCharacterRepository(
+    private val dataSource: KtorCharacterDataSource,
+) : CharacterRepository {
+    override suspend fun getCharacters(page: Int): Result<CharactersPage, DataError> =
+        dataSource.getCharacters(page).map { it.toDomain() }
+
+    override suspend fun getCharacterDetails(id: Int): Result<CharacterDetails, DataError> =
+        dataSource.getCharacter(id).map { it.toCharacterDetails() }
+}

feature/characters/data/src/main/kotlin/com/example/architecture/feature/characters/data/datasource/KtorCharacterDataSource.kt

@@ -0,0 +1,22 @@
+package com.example.architecture.feature.characters.data.datasource
+
+import com.example.architecture.core.data.network.get
+import com.example.architecture.core.domain.DataError
+import com.example.architecture.core.domain.Result
+import com.example.architecture.feature.characters.data.dto.CharacterDto
+import com.example.architecture.feature.characters.data.dto.CharactersResponseDto
+import io.ktor.client.HttpClient
+
+/**
+ * Remote data source for characters. Returns raw DTOs (no mapping here — the repository maps via
+ * CharacterMapper). Errors already surface as [DataError.Network] from the typed `get` helper.
+ */
+internal class KtorCharacterDataSource(
+    private val httpClient: HttpClient,
+) {
+    suspend fun getCharacters(page: Int): Result<CharactersResponseDto, DataError.Network> =
+        httpClient.get(route = "/character", queryParameters = mapOf("page" to page))
+
+    suspend fun getCharacter(id: Int): Result<CharacterDto, DataError.Network> =
+        httpClient.get(route = "/character/$id")
+}

feature/characters/data/src/main/kotlin/com/example/architecture/feature/characters/data/di/CharactersDataModule.kt

@@ -0,0 +1,13 @@
+package com.example.architecture.feature.characters.data.di
+
+import com.example.architecture.feature.characters.data.NetworkCharacterRepository
+import com.example.architecture.feature.characters.data.datasource.KtorCharacterDataSource
+import com.example.architecture.feature.characters.domain.CharacterRepository
+import org.koin.core.module.dsl.bind
+import org.koin.core.module.dsl.singleOf
+import org.koin.dsl.module
+
+val charactersDataModule = module {
+    singleOf(::KtorCharacterDataSource)
+    singleOf(::NetworkCharacterRepository) { bind<CharacterRepository>() }
+}

feature/characters/data/src/main/kotlin/com/example/architecture/feature/characters/data/dto/CharacterDto.kt

@@ -0,0 +1,23 @@
+package com.example.architecture.feature.characters.data.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class CharacterDto(
+    val id: Int,
+    val name: String,
+    val status: String,
+    val species: String,
+    val type: String,
+    val gender: String,
+    val origin: LocationRefDto,
+    val location: LocationRefDto,
+    val image: String,
+    val episode: List<String>,
+)
+
+@Serializable
+data class LocationRefDto(
+    val name: String,
+    val url: String,
+)

feature/characters/data/src/main/kotlin/com/example/architecture/feature/characters/data/dto/CharactersResponseDto.kt

@@ -0,0 +1,9 @@
+package com.example.architecture.feature.characters.data.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class CharactersResponseDto(
+    val info: PageInfoDto,
+    val results: List<CharacterDto>,
+)

feature/characters/data/src/main/kotlin/com/example/architecture/feature/characters/data/dto/PageInfoDto.kt

@@ -0,0 +1,11 @@
+package com.example.architecture.feature.characters.data.dto
+
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class PageInfoDto(
+    val count: Int,
+    val pages: Int,
+    val next: String?,
+    val prev: String?,
+)

feature/characters/data/src/main/kotlin/com/example/architecture/feature/characters/data/mappers/CharacterMapper.kt

@@ -0,0 +1,44 @@
+package com.example.architecture.feature.characters.data.mappers
+
+import com.example.architecture.feature.characters.data.dto.CharacterDto
+import com.example.architecture.feature.characters.data.dto.CharactersResponseDto
+import com.example.architecture.feature.characters.domain.model.Character
+import com.example.architecture.feature.characters.domain.model.CharacterDetails
+import com.example.architecture.feature.characters.domain.model.CharacterStatus
+import com.example.architecture.feature.characters.domain.model.CharactersPage
+
+internal fun CharactersResponseDto.toDomain(): CharactersPage = CharactersPage(
+    characters = results.map { it.toCharacter() },
+    nextPage = info.next?.toPageNumber(),
+)
+
+internal fun CharacterDto.toCharacter(): Character = Character(
+    id = id,
+    name = name,
+    status = status.toCharacterStatus(),
+    species = species,
+    imageUrl = image,
+)
+
+internal fun CharacterDto.toCharacterDetails(): CharacterDetails = CharacterDetails(
+    id = id,
+    name = name,
+    status = status.toCharacterStatus(),
+    species = species,
+    type = type,
+    gender = gender,
+    origin = origin.name,
+    location = location.name,
+    imageUrl = image,
+    episodeCount = episode.size,
+)
+
+private fun String.toCharacterStatus(): CharacterStatus = when (lowercase()) {
+    "alive" -> CharacterStatus.ALIVE
+    "dead" -> CharacterStatus.DEAD
+    else -> CharacterStatus.UNKNOWN
+}
+
+/** The API's `next` is a full URL like `.../character?page=2`; pull the page number out of it. */
+private fun String.toPageNumber(): Int? =
+    Regex("[?&]page=(\\d+)").find(this)?.groupValues?.getOrNull(1)?.toIntOrNull()