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.

core/data/src/main/AndroidManifest.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <!-- Networking lives in this module, so the permission is declared here and merges into :app. -->
+    <uses-permission android:name="android.permission.INTERNET" />
+
+</manifest>