feat(audit)!: ScadaBridge C5 — collapse central dbo.AuditLog to 10 canonical cols + persisted computed cols; CollapseAuditLogToCanonical migration; repo writes canonical directly (Task 2.5)

src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/ScadaBridgeDbContext.cs

@@ -154,6 +154,43 @@ public class ScadaBridgeDbContext : DbContext, IDataProtectionKeyContext
         modelBuilder.ApplyConfigurationsFromAssembly(typeof(ScadaBridgeDbContext).Assembly);
 
         ApplySecretColumnEncryption(modelBuilder);
+
+        NeutralizeSqlServerComputedColumnsForNonSqlServerProviders(modelBuilder);
+    }
+
+    /// <summary>
+    /// C5 (Task 2.5): the central <c>dbo.AuditLog</c> persisted computed columns use
+    /// SQL Server's <c>JSON_VALUE</c> expression, which only SQL Server can evaluate.
+    /// On a non-SQL-Server provider (the SQLite test contexts) emitting that SQL in a
+    /// <c>CREATE TABLE</c> fails ("no such function: JSON_VALUE"). Strip the
+    /// computed-column SQL for any non-SQL-Server provider so those columns degrade to
+    /// plain (always-null on the test provider) nullable columns; SQL Server keeps the
+    /// real <c>… AS JSON_VALUE(...) PERSISTED</c> definitions. This is a model-shape
+    /// adaptation only — it never runs under the design-time SQL Server provider, so the
+    /// migration / model-snapshot remain the canonical SQL Server shape.
+    /// </summary>
+    private void NeutralizeSqlServerComputedColumnsForNonSqlServerProviders(ModelBuilder modelBuilder)
+    {
+        // Database.IsSqlServer() reads the configured provider — true for production and
+        // for the design-time factory (UseSqlServer), false for the SQLite test contexts.
+        if (Database.IsSqlServer())
+        {
+            return;
+        }
+
+        foreach (var entityType in modelBuilder.Model.GetEntityTypes())
+        {
+            foreach (var property in entityType.GetProperties())
+            {
+                if (property.GetComputedColumnSql() is not null)
+                {
+                    property.SetComputedColumnSql(null);
+                    property.SetColumnType(null);
+                    property.ValueGenerated = Microsoft.EntityFrameworkCore.Metadata.ValueGenerated.Never;
+                    property.SetAfterSaveBehavior(Microsoft.EntityFrameworkCore.Metadata.PropertySaveBehavior.Save);
+                }
+            }
+        }
     }
 
     /// <inheritdoc />