Convert Projects module to MediatR commands/queries

Replaces IProjectService/ProjectService. IProjectMemberService is
left in place for now — ProjectMembersController still depends on it
until the next task converts it too.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

mws.application/Projects/Commands/UpdateProject.cs

@@ -0,0 +1,35 @@
+using AutoMapper;
+using MediatR;
+using Mws.Application.Common;
+using Mws.Domain.Projects;
+
+namespace Mws.Application.Projects;
+
+public record UpdateProjectCommand(Guid UserId, Guid ProjectId, UpdateProjectRequest Request) : IRequest<ProjectDto>;
+
+public class UpdateProjectHandler(IUnitOfWork uow, IMapper mapper) : IRequestHandler<UpdateProjectCommand, ProjectDto>
+{
+    public async Task<ProjectDto> Handle(UpdateProjectCommand command, CancellationToken ct)
+    {
+        var project = await ProjectAccess.GetForUserOrThrowAsync(uow, command.UserId, command.ProjectId, ct);
+
+        if (MemberRole.Owner != await uow.Projects.GetMemberRoleAsync(command.ProjectId, command.UserId, ct))
+        {
+            throw new ForbiddenException("Only the project owner can update the project");
+        }
+
+        var request = command.Request;
+        if (string.IsNullOrWhiteSpace(request.Name))
+        {
+            throw new BadRequestException("Project name is required");
+        }
+
+        project.Name = request.Name.Trim();
+        project.Description = request.Description;
+        project.Status = request.Status;
+        project.UpdatedAt = DateTime.UtcNow;
+
+        await uow.SaveChangesAsync(ct);
+        return mapper.Map<ProjectDto>(project);
+    }
+}