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>

Directory.Packages.props

@@ -24,5 +24,7 @@
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.8.1" />
     <PackageVersion Include="xunit" Version="2.9.3" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="3.1.5" />
+    <PackageVersion Include="Moq" Version="4.20.70" />
+    <PackageVersion Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="10.0.0" />
   </ItemGroup>
 </Project>