Add audit logs.

API/ROLAC.API/Data/AppDbContext.cs

@@ -1,5 +1,6 @@
 using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
 using Microsoft.EntityFrameworkCore;
+using ROLAC.API.Data.Logging;
 using ROLAC.API.Entities;
 
 namespace ROLAC.API.Data;
@@ -324,5 +325,12 @@ public class AppDbContext : IdentityDbContext<AppUser, AppRole, string>
             entity.Property(e => e.UpdatedBy).HasMaxLength(450);
             entity.HasIndex(e => new { e.Year, e.Month }).IsUnique();
         });
+
+        // ── SystemLog / AuditLog (append-only) ───────────────────────────────
+        // Mapped here for SCHEMA only — there are deliberately no DbSets on this
+        // context, so business code can't write logs through the audited context.
+        // Runtime reads/writes go through the dedicated LogDbContext. Including
+        // them in the model lets the single startup migration create the tables.
+        LogModelConfiguration.Configure(builder);
     }
 }