Commit MWS backend source tree

The ASP.NET Core solution (mws.api/mws.application/mws.domain/
mws.infrastructure) existed only as untracked working files. Adding
it to version control, plus a .gitignore for build output and local
tooling directories, so the CQRS/mediator refactor plan has a real
git history to branch and diff against.

mws.application/Common/Repositories/IUserRepository.cs

@@ -0,0 +1,14 @@
+using Mws.Domain.Users;
+
+namespace Mws.Application.Common.Repositories;
+
+public interface IUserRepository : IRepository<User>
+{
+    Task<User?> GetByIdAsync(Guid id, CancellationToken ct = default);
+    Task<User?> GetByIdWithRoleAsync(Guid id, CancellationToken ct = default);
+    Task<User?> GetByUsernameWithRoleAsync(string username, CancellationToken ct = default);
+    Task<bool> ExistsByUsernameAsync(string username, CancellationToken ct = default);
+    Task<bool> ExistsByRoleIdAsync(Guid roleId, CancellationToken ct = default);
+    Task<Guid> GetRoleIdAsync(Guid userId, CancellationToken ct = default);
+    Task<List<User>> SearchWithRoleAsync(string? term, int? take, CancellationToken ct = default);
+}