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

masterdata/masterdata-service/src/main/kotlin/at/mocode/masterdata/service/MasterdataServiceApplication.kt

@@ -0,0 +1,19 @@
+package at.mocode.masterdata.service
+
+import org.springframework.boot.autoconfigure.SpringBootApplication
+import org.springframework.boot.runApplication
+
+/**
+ * Main application class for the Masterdata Service.
+ *
+ * This service provides APIs for managing master data such as countries, regions, and other reference data.
+ */
+@SpringBootApplication
+class MasterdataServiceApplication
+
+/**
+ * Main entry point for the Masterdata Service application.
+ */
+fun main(args: Array<String>) {
+    runApplication<MasterdataServiceApplication>(*args)
+}