DAR-147 — Add admin user management and Keycloak JWT resource server
- Add admin user management REST API (/api/auth/admin/users) with CRUD endpoints: list (paginated/filterable), get by ID, batch fetch, create, change status, change role
- Add AdminUserServiceImpl delegating to Keycloak Admin API + AdminUser PostgreSQL table (from darvest-common)
- Add KeycloakJwtAuthenticationConverterConfig extracting realm_access.roles from Keycloak JWTs and mapping them to Spring ROLE_ authorities
- Overhaul SecurityConfiguration: wire OAuth2 resource server with JWT validation, protect /api/auth/admin/** with role-based access, enable @PreAuthorize method security
- Extend Application.java to scan darvest-common admin entities and local AdminUserRepository
- Add darvest-common:0.0.24-RELEASE dependency to pom.xml
- Add spring.security.oauth2.resourceserver.jwt config to all profiles; align docker-compose.yml to pre-rec DB credentials and port 5431
Closes DAR-147