fix: address full-codebase CodeRabbit review findings (48 fixes)

.gitignore

@@ -4,9 +4,9 @@
 /WSIST/WSIST.Web/wwwroot/lib
 /WSIST/WSIST.Web/bin
 /WSIST/WSIST.UnitTests/obj
-/WSIST/WSIST.UnitTests/obj
-WSIST/WSIST.UnitTests/obj/Debug/net9.0/WSIST.UnitTests.csproj.AssemblyReference.cache
-/WSIST/WSIST.UnitTests/obj
 /WSIST/WSIST.UnitTests/bin
-WSIST/WSIST.Engine/bin
-WSIST/WSIST.Web/appsettings.Development.json
+/WSIST/WSIST.Engine/bin
+/WSIST/WSIST.Web/appsettings.Development.json
+.claude
+.env
+coderabbit-full-review*.txt

WSIST/.config/dotnet-tools.json

@@ -3,7 +3,7 @@
   "isRoot": true,
   "tools": {
     "csharpier": {
-      "version": "1.2.4",
+      "version": "1.3.0",
       "commands": [
         "csharpier"
       ],

WSIST/.env.example

@@ -0,0 +1,3 @@
+# Copy to .env and customize. Used by docker-compose.yml for the local MySQL container.
+MYSQL_ROOT_PASSWORD=password
+MYSQL_DATABASE=wsistdb

WSIST/WSIST.Engine/Migrations/20260611100206_SubjectIdAutoIncrement.cs

@@ -0,0 +1,64 @@
+using Microsoft.EntityFrameworkCore.Metadata;
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+#pragma warning disable CA1814 // Prefer jagged arrays over multidimensional
+
+namespace WSIST.Engine.Migrations
+{
+    /// <inheritdoc />
+    public partial class SubjectIdAutoIncrement : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            // Move the seeded system subjects from ids 0..5 to -6..-1 *in place*
+            // (renumbering instead of delete+insert keeps every Tests.Subject
+            // reference intact), then turn the column into auto-increment so
+            // user-created subjects get database-generated ids. Renumbering must
+            // happen first: MySQL won't accept an auto-increment column that
+            // still holds a 0. FK checks stay off through the ALTER because the
+            // column is referenced by FK_Tests_Subjects_Subject.
+            migrationBuilder.Sql("SET FOREIGN_KEY_CHECKS = 0;");
+            migrationBuilder.Sql("UPDATE `Subjects` SET `Id` = `Id` - 6 WHERE `IsSystem` = 1 AND `Id` BETWEEN 0 AND 5;");
+            migrationBuilder.Sql("UPDATE `Tests` SET `Subject` = `Subject` - 6 WHERE `Subject` BETWEEN 0 AND 5;");
+
+            migrationBuilder.AlterColumn<int>(
+                name: "Id",
+                table: "Subjects",
+                type: "int",
+                nullable: false,
+                oldClrType: typeof(int),
+                oldType: "int")
+                .Annotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn);
+
+            migrationBuilder.Sql("SET FOREIGN_KEY_CHECKS = 1;");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            // Rollback limitation: if user-created subjects have claimed
+            // auto-increment ids 1..5 since the Up ran, shifting the system
+            // subjects back from -6..-1 to 0..5 would collide with them on the
+            // primary key and this migration would fail. There is no safe,
+            // automatic resolution — those user subjects would have to be
+            // renumbered manually first.
+            migrationBuilder.Sql("SET FOREIGN_KEY_CHECKS = 0;");
+
+            migrationBuilder.AlterColumn<int>(
+                name: "Id",
+                table: "Subjects",
+                type: "int",
+                nullable: false,
+                oldClrType: typeof(int),
+                oldType: "int")
+                .OldAnnotation("MySql:ValueGenerationStrategy", MySqlValueGenerationStrategy.IdentityColumn);
+
+            migrationBuilder.Sql("UPDATE `Subjects` SET `Id` = `Id` + 6 WHERE `IsSystem` = 1 AND `Id` BETWEEN -6 AND -1;");
+            migrationBuilder.Sql("UPDATE `Tests` SET `Subject` = `Subject` + 6 WHERE `Subject` BETWEEN -6 AND -1;");
+            migrationBuilder.Sql("SET FOREIGN_KEY_CHECKS = 1;");
+        }
+    }
+}

WSIST/WSIST.Engine/Migrations/WsistContextModelSnapshot.cs

@@ -17,16 +17,19 @@ protected override void BuildModel(ModelBuilder modelBuilder)
         {
 #pragma warning disable 612, 618
             modelBuilder
-                .HasAnnotation("ProductVersion", "9.0.0")
+                .HasAnnotation("ProductVersion", "9.0.17")
                 .HasAnnotation("Relational:MaxIdentifierLength", 64);
 
             MySqlModelBuilderExtensions.AutoIncrementColumns(modelBuilder);
 
             modelBuilder.Entity("WSIST.Engine.Subject", b =>
                 {
                     b.Property<int>("Id")
+                        .ValueGeneratedOnAdd()
                         .HasColumnType("int");
 
+                    MySqlPropertyBuilderExtensions.UseMySqlIdentityColumn(b.Property<int>("Id"));
+
                     b.Property<bool>("IsSystem")
                         .ValueGeneratedOnAdd()
                         .HasColumnType("tinyint(1)")
@@ -49,37 +52,37 @@ protected override void BuildModel(ModelBuilder modelBuilder)
                     b.HasData(
                         new
                         {
-                            Id = 0,
+                            Id = -6,
                             IsSystem = true,
                             Name = "Math"
                         },
                         new
                         {
-                            Id = 1,
+                            Id = -5,
                             IsSystem = true,
                             Name = "English"
                         },
                         new
                         {
-                            Id = 2,
+                            Id = -4,
                             IsSystem = true,
                             Name = "French"
                         },
                         new
                         {
-                            Id = 3,
+                            Id = -3,
                             IsSystem = true,
                             Name = "German"
                         },
                         new
                         {
-                            Id = 4,
+                            Id = -2,
                             IsSystem = true,
                             Name = "Chemistry"
                         },
                         new
                         {
-                            Id = 5,
+                            Id = -1,
                             IsSystem = true,
                             Name = "Other"
                         });

WSIST/WSIST.Engine/Test.cs

@@ -65,9 +65,9 @@ public static string VolumeHelper(TestVolume volume)
         return "Please Choose a Setting";
     }
 
-    public static string UnderstandingHelper(PersonalUnderstanding volume)
+    public static string UnderstandingHelper(PersonalUnderstanding understanding)
     {
-        switch (volume)
+        switch (understanding)
         {
             case PersonalUnderstanding.VeryLow:
             {