Integrate Ktor HTTP clients and repositories for Veranstalter and Turnier features:

- Add `ApiRoutes` for central backend routing configuration.
- Implement `DefaultVeranstalterRepository` and `DefaultTurnierRepository` with Ktor clients.
- Add domain models (`Turnier`, `Bewerb`, `Abteilung`, `Veranstalter`) and respective repository interfaces.
- Replace fake VeranstalterRepository with real implementation.
- Update DI with `veranstalterModule` and HTTP client injection.
- Simplify TokenProvider and update HttpClient setup (timeouts, retries, logging).
- Mark roadmap tasks B-2 as partially complete.

frontend/features/turnier-feature/src/commonMain/kotlin/at/mocode/turnier/feature/domain/AbteilungRepository.kt

@@ -0,0 +1,15 @@
+package at.mocode.turnier.feature.domain
+
+data class Abteilung(
+  val id: Long,
+  val bewerbId: Long,
+  val name: String,
+)
+
+interface AbteilungRepository {
+  suspend fun list(bewerbId: Long): Result<List<Abteilung>>
+  suspend fun getById(id: Long): Result<Abteilung>
+  suspend fun create(model: Abteilung): Result<Abteilung>
+  suspend fun update(id: Long, model: Abteilung): Result<Abteilung>
+  suspend fun delete(id: Long): Result<Unit>
+}

frontend/features/turnier-feature/src/commonMain/kotlin/at/mocode/turnier/feature/domain/BewerbRepository.kt

@@ -0,0 +1,15 @@
+package at.mocode.turnier.feature.domain
+
+data class Bewerb(
+  val id: Long,
+  val turnierId: Long,
+  val name: String,
+)
+
+interface BewerbRepository {
+  suspend fun list(turnierId: Long): Result<List<Bewerb>>
+  suspend fun getById(id: Long): Result<Bewerb>
+  suspend fun create(model: Bewerb): Result<Bewerb>
+  suspend fun update(id: Long, model: Bewerb): Result<Bewerb>
+  suspend fun delete(id: Long): Result<Unit>
+}

frontend/features/turnier-feature/src/commonMain/kotlin/at/mocode/turnier/feature/domain/TurnierRepository.kt

@@ -0,0 +1,14 @@
+package at.mocode.turnier.feature.domain
+
+data class Turnier(
+  val id: Long,
+  val name: String,
+)
+
+interface TurnierRepository {
+  suspend fun list(): Result<List<Turnier>>
+  suspend fun getById(id: Long): Result<Turnier>
+  suspend fun create(model: Turnier): Result<Turnier>
+  suspend fun update(id: Long, model: Turnier): Result<Turnier>
+  suspend fun delete(id: Long): Result<Unit>
+}