feat(characters): Koin module + nav graph + wire into :app (REDI-89)

- charactersPresentationModule: viewModelOf(::CharacterListViewModel) (in the UI-agnostic module).
- @Serializable CharacterListRoute + NavGraphBuilder.charactersGraph { composable<CharacterListRoute> }
  in presentation-compose (serialization plugin added for type-safe routes).
- :app registers coreDataModule + charactersDataModule + charactersPresentationModule in startKoin,
  and hosts a NavHost(startDestination = CharacterListRoute) calling charactersGraph.
- core:data manifest declares INTERNET (merges into :app) for live API calls.

app/build.gradle.kts

@@ -16,10 +16,16 @@ dependencies {
     implementation(project(":core:data"))
     implementation(project(":core:design-system"))
 
+    // Characters feature: data + presentation (Koin modules) + Compose renderer (nav graph).
+    implementation(project(":feature:characters:data"))
+    implementation(project(":feature:characters:presentation"))
+    implementation(project(":feature:characters:presentation-compose"))
+
     implementation(libs.androidx.core.ktx)
     implementation(libs.androidx.activity.compose)
     implementation(libs.androidx.lifecycle.runtime.ktx)
     implementation(libs.bundles.lifecycle.compose)
+    implementation(libs.androidx.navigation.compose)
     // Material Components — required for the Material3 XML Activity theme.
     implementation(libs.material)
     // Logging — the DebugTree is planted here; other modules log via Timber's static API.