WIP: AEG-VS-01-04 Part 2 - DI setup + Endpoint refactoring (token budget constraint)

- Added IdentityAccessModule.cs with DI registration
- Added KArtSell.Modules.IdentityAccess.csproj with FastEndpoints deps
- Added project files for UnitTests & IntegrationTests
- Updated Program.cs to register IdentityAccessModule
- Updated Host.csproj to reference IdentityAccess module
- Fixed Directory.Packages.props with Moq + MS.Extensions.DependencyInjection

ISSUES (to fix next session):
- FastEndpoints Send/SendAsync/SendOkAsync method resolution incomplete
- Response record initialization requires field values
- Need to refactor endpoints to match ModelOperations pattern exactly

WORKING:
- Domain layer (IdentityState, RoleAssignmentState) ✅
- SQL repositories (Dapper) ✅
- Unit tests (RegisterIdentity, RequestMfaSetup handlers) ✅
- Integration test structure ready ✅

Next: Simplify endpoints using 'Endpoint<Req,Resp>' pattern from GetApprovalQueue sample

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

tests/KArtSell.IdentityAccess.UnitTests/ManageIdentityAndRoles/IdentityStateTests.cs

@@ -61,14 +61,14 @@ public class IdentityStateTests
         foreach (var state in states)
         {
             var deactivated = state.Deactivate();
-            Assert.Equal(IdentityState.Inactive, deactivated.Value);
+            Assert.Equal("INACTIVE", deactivated.Value);
         }
     }
 
     [Fact]
     public void CanRevokeFromInactive()
     {
-        var state = IdentityState.Parse(IdentityState.Inactive);
+        var state = IdentityState.CreateInactive();
         var revoked = state.Revoke();
 
         Assert.Equal(IdentityState.Revoked, revoked.Value);