Phase 1 WP-2–10: Repositories, audit service, security & auth (LDAP, JWT, roles, policies, data protection)

- WP-2: SecurityRepository + CentralUiRepository with audit log queries
- WP-3: AuditService with transactional guarantee (same SaveChangesAsync)
- WP-4: Optimistic concurrency tests (deployment records vs template last-write-wins)
- WP-5: Seed data (SCADA-Admins → Admin role mapping)
- WP-6: LdapAuthService (direct bind, TLS enforcement, group query)
- WP-7: JwtTokenService (HMAC-SHA256, 15-min refresh, 30-min idle timeout)
- WP-8: RoleMapper (LDAP groups → roles with site-scoped deployment)
- WP-9: Authorization policies (Admin/Design/Deployment + site scope handler)
- WP-10: Shared Data Protection keys via EF Core
141 tests pass, zero warnings.

src/ScadaLink.Commons/Entities/Security/LdapGroupMapping.cs

@@ -6,6 +6,9 @@ public class LdapGroupMapping
     public string LdapGroupName { get; set; }
     public string Role { get; set; }
 
+    // Parameterless constructor for EF Core seed data
+    private LdapGroupMapping() { LdapGroupName = null!; Role = null!; }
+
     public LdapGroupMapping(string ldapGroupName, string role)
     {
         LdapGroupName = ldapGroupName ?? throw new ArgumentNullException(nameof(ldapGroupName));