refactor: Migrate from monolithic to modular architecture

- Restructure project into domain-specific modules (core, masterdata, members, horses, events, infrastructure)
- Create shared client components in common-ui module
- Implement CI/CD workflows with GitHub Actions
- Consolidate documentation in docs directory
- Remove deprecated modules and documentation files
- Add cleanup and migration scripts for transition
- Update README with new project structure and setup instructions

infrastructure/auth/auth-client/build.gradle.kts

@@ -0,0 +1,20 @@
+plugins {
+    kotlin("jvm")
+    kotlin("plugin.spring")
+}
+
+dependencies {
+    implementation(projects.platform.platformDependencies)
+    implementation(projects.core.coreDomain)
+    implementation(projects.core.coreUtils)
+
+    // Spring Security
+    implementation("org.springframework.boot:spring-boot-starter-oauth2-client")
+    implementation("org.springframework.boot:spring-boot-starter-security")
+    implementation("org.springframework.security:spring-security-oauth2-jose")
+
+    // JWT
+    implementation("com.auth0:java-jwt:4.4.0")
+
+    testImplementation(projects.platform.platformTesting)
+}