feat(build): Refactor infrastructure modules and establish single source of truth

This commit introduces a major refactoring of the build system and the core infrastructure modules. The primary goal is to establish a strict "Single Source of Truth" for all dependencies using Gradle Version Catalogs and to create a clean, maintainable, and scalable foundation for all current and future services.

### 1. Centralized Dependency Management (`libs.versions.toml`)

- **Established Single Source of Truth:** All dependency versions are now exclusively managed in `gradle/libs.versions.toml`. Hardcoded versions have been removed from all build scripts.
- **Introduced Gradle Bundles:** To simplify module dependencies, several bundles have been created (e.g., `testing-jvm`, `redis-cache`, `spring-cloud-gateway`, `monitoring-client`). This drastically reduces boilerplate in the `build.gradle.kts` files and improves readability.
- **Cleaned up Aliases:** All library and plugin aliases have been standardized for consistency.

### 2. Infrastructure Module Refactoring

All infrastructure modules (`core`, `platform`, `auth`, `cache`, `event-store`, `messaging`, `monitoring`, `gateway`) have been refactored to align with the new dependency management strategy.

- **Simplified Build Scripts:** The `build.gradle.kts` for each module now uses the new bundles and aliases, making them significantly cleaner and easier to understand.
- **Consistent Structure:** The architecture of each module now clearly follows the Port-Adapter pattern where applicable (e.g., `cache-api`/`redis-cache`).
- **Standardized `platform-bom`:** The project's own Bill of Materials (`platform-bom`) now also includes the Spring Cloud BOM, ensuring version consistency for all Spring-related dependencies.

### 3. Added Infrastructure Documentation

To improve onboarding and architectural understanding, a dedicated `README-*.md` file has been created for each refactored infrastructure module:
- `README-CORE.md`
- `README-PLATFORM.md`
- `README-INFRA-AUTH.md`
- `README-INFRA-CACHE.md`
- `README-INFRA-EVENT-STORE.md`
- `README-INFRA-MESSAGING.md`
- `README-INFRA-MONITORING.md`
- `README-INFRA-GATEWAY.md`

These documents explain the purpose, architecture, and usage of each component within the system. This lays the groundwork for our "Tracer Bullet" development approach.

infrastructure/gateway/build.gradle.kts

@@ -1,9 +1,9 @@
-plugins {
+/*plugins {
     alias(libs.plugins.kotlin.jvm)
     alias(libs.plugins.kotlin.serialization)
     alias(libs.plugins.ktor)
-    application
     alias(libs.plugins.spring.dependencyManagement)
+    application
 }
 
 application {
@@ -12,18 +12,13 @@ application {
 
 dependencies {
     api(platform(libs.spring.boot.dependencies))
-    // --- Interne Module ---
-    // Der Gateway benötigt nur die Kern-Definitionen und Utilities.
     implementation(projects.platform.platformDependencies)
     implementation(projects.core.coreDomain)
     implementation(projects.core.coreUtils)
-    // Der Gateway nutzt den Auth-Client, um Tokens zu validieren.
+
     implementation(projects.infrastructure.auth.authClient)
     implementation(projects.infrastructure.monitoring.monitoringClient)
 
-    // !!! WICHTIG: KEINE direkten Abhängigkeiten zu den Domänen- oder
-    // Infrastruktur-Modulen der Backend-Services mehr!
-
     // --- Ktor Server ---
     implementation(libs.ktor.server.core)
     implementation(libs.ktor.server.netty)
@@ -44,7 +39,7 @@ dependencies {
 
     // --- Ktor Client (damit der Gateway Anfragen an die Backend-Services weiterleiten kann) ---
     implementation(libs.ktor.client.core)
-    implementation(libs.ktor.client.cio) // CIO ist eine gute, asynchrone Engine
+    implementation(libs.ktor.client.cio)
     implementation(libs.ktor.client.contentNegotiation)
     implementation(libs.ktor.client.serialization.kotlinx.json)
 
@@ -54,4 +49,38 @@ dependencies {
     // --- Testing ---
     testImplementation(projects.platform.platformTesting)
     testImplementation(libs.ktor.server.tests)
+}*/
+
+// Dieses Modul ist das API-Gateway und der einzige öffentliche Einstiegspunkt
+// für alle externen Anfragen an das Meldestelle-System.
+plugins {
+    alias(libs.plugins.kotlin.jvm)
+    alias(libs.plugins.kotlin.spring)
+    alias(libs.plugins.spring.boot)
+    alias(libs.plugins.spring.dependencyManagement)
+}
+
+// Konfiguriert die Hauptklasse für das ausführbare JAR.
+springBoot {
+    mainClass.set("at.mocode.infrastructure.gateway.GatewayApplicationKt")
+}
+
+dependencies {
+    // Stellt sicher, dass alle Versionen aus der zentralen BOM kommen.
+    implementation(platform(projects.platform.platformBom))
+    // Stellt gemeinsame Abhängigkeiten bereit.
+    implementation(projects.platform.platformDependencies)
+
+    // OPTIMIERUNG: Verwendung des `spring-cloud-gateway`-Bundles.
+    // Es enthält den Gateway-Starter und den Consul Discovery Client.
+    implementation(libs.bundles.spring.cloud.gateway)
+
+    // Bindet die wiederverwendbare Logik zur JWT-Validierung ein.
+    implementation(projects.infrastructure.auth.authClient)
+
+    // Bindet die wiederverwendbare Logik für Metriken und Tracing ein.
+    implementation(projects.infrastructure.monitoring.monitoringClient)
+
+    // Stellt alle Test-Abhängigkeiten gebündelt bereit.
+    testImplementation(projects.platform.platformTesting)
 }