fix(db): update migration and configure many-to-many relationships to avoid cascade paths

- Regenerated InitialCreate migration to reflect new entity configurations
- Configured many-to-many relationship between CostCycle and Unit with NoAction on Unit side to prevent multiple cascade paths
- Updated UnitCost relationships: Cascade from CostCycle, NoAction from Unit
- Removed commented-out global filter code and replaced with explicit relationship configurations

Complex.EndPoint/Program.cs

@@ -200,8 +200,8 @@ using (var scope = app.Services.CreateScope())
                     "BEGIN " +
                     "CREATE TABLE [__EFMigrationsHistory] ([MigrationId] nvarchar(150) NOT NULL, [ProductVersion] nvarchar(32) NOT NULL, PRIMARY KEY ([MigrationId])); " +
                     "END " +
-                    "IF NOT EXISTS (SELECT * FROM __EFMigrationsHistory WHERE MigrationId = '20260608224155_InitialCreate') " +
-                    "INSERT INTO __EFMigrationsHistory (MigrationId, ProductVersion) VALUES ('20260608224155_InitialCreate', '6.0.3')");
+                    "IF NOT EXISTS (SELECT * FROM __EFMigrationsHistory WHERE MigrationId = '20260608225159_InitialCreate') " +
+                    "INSERT INTO __EFMigrationsHistory (MigrationId, ProductVersion) VALUES ('20260608225159_InitialCreate', '6.0.3')");
             }
         }
         catch