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.

tests/ScadaLink.ConfigurationDatabase.Tests/SqliteTestHelper.cs

@@ -0,0 +1,75 @@
+using Microsoft.EntityFrameworkCore;
+using Microsoft.EntityFrameworkCore.Diagnostics;
+using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
+using ScadaLink.ConfigurationDatabase;
+
+namespace ScadaLink.ConfigurationDatabase.Tests;
+
+/// <summary>
+/// Test DbContext that maps DateTimeOffset to a sortable string format for SQLite.
+/// EF Core 10 SQLite provider does not support ORDER BY on DateTimeOffset columns.
+/// </summary>
+public class SqliteTestDbContext : ScadaLinkDbContext
+{
+    public SqliteTestDbContext(DbContextOptions<ScadaLinkDbContext> options) : base(options)
+    {
+    }
+
+    protected override void OnModelCreating(ModelBuilder modelBuilder)
+    {
+        base.OnModelCreating(modelBuilder);
+
+        // Convert DateTimeOffset to ISO 8601 string for SQLite so ORDER BY works
+        var converter = new ValueConverter<DateTimeOffset, string>(
+            v => v.UtcDateTime.ToString("o"),
+            v => DateTimeOffset.Parse(v));
+
+        var nullableConverter = new ValueConverter<DateTimeOffset?, string?>(
+            v => v.HasValue ? v.Value.UtcDateTime.ToString("o") : null,
+            v => v != null ? DateTimeOffset.Parse(v) : null);
+
+        foreach (var entityType in modelBuilder.Model.GetEntityTypes())
+        {
+            foreach (var property in entityType.GetProperties())
+            {
+                if (property.ClrType == typeof(DateTimeOffset))
+                {
+                    property.SetValueConverter(converter);
+                    property.SetColumnType("TEXT");
+                }
+                else if (property.ClrType == typeof(DateTimeOffset?))
+                {
+                    property.SetValueConverter(nullableConverter);
+                    property.SetColumnType("TEXT");
+                }
+            }
+        }
+    }
+}
+
+public static class SqliteTestHelper
+{
+    public static ScadaLinkDbContext CreateInMemoryContext()
+    {
+        var options = new DbContextOptionsBuilder<ScadaLinkDbContext>()
+            .UseSqlite("DataSource=:memory:")
+            .ConfigureWarnings(w => w.Ignore(RelationalEventId.PendingModelChangesWarning))
+            .Options;
+
+        var context = new SqliteTestDbContext(options);
+        context.Database.OpenConnection();
+        context.Database.EnsureCreated();
+        return context;
+    }
+
+    public static ScadaLinkDbContext CreateFileContext(string dbPath)
+    {
+        var options = new DbContextOptionsBuilder<ScadaLinkDbContext>()
+            .UseSqlite($"DataSource={dbPath}")
+            .ConfigureWarnings(w => w.Ignore(RelationalEventId.PendingModelChangesWarning))
+            .Options;
+
+        var context = new SqliteTestDbContext(options);
+        return context;
+    }
+}