Convert ProjectMembers module to MediatR commands/queries

Replaces IProjectMemberService/ProjectMemberService, completing the
Projects module conversion.

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

mws.application/Projects/Commands/AddProjectMember.cs

@@ -0,0 +1,61 @@
+using MediatR;
+using Mws.Application.Common;
+using Mws.Domain.Projects;
+
+namespace Mws.Application.Projects;
+
+public record AddProjectMemberCommand(Guid UserId, Guid ProjectId, AddMemberRequest Request) : IRequest<ProjectMemberDto>;
+
+public class AddProjectMemberHandler(IUnitOfWork uow) : IRequestHandler<AddProjectMemberCommand, ProjectMemberDto>
+{
+    public async Task<ProjectMemberDto> Handle(AddProjectMemberCommand command, CancellationToken ct)
+    {
+        if (await uow.Projects.GetMemberRoleAsync(command.ProjectId, command.UserId, ct) != MemberRole.Owner)
+        {
+            throw new ForbiddenException("Only the project owner can add members");
+        }
+
+        var request = command.Request;
+        var user = await uow.Users.GetByIdAsync(request.UserId, ct)
+            ?? throw new NotFoundException("User not found");
+
+        var already = await uow.Projects.IsMemberAsync(command.ProjectId, request.UserId, ct);
+        if (already)
+        {
+            throw new BadRequestException("User is already a member of this project");
+        }
+
+        var role = request.Role is MemberRole.Owner or MemberRole.Member ? request.Role : MemberRole.Member;
+        var member = new ProjectMember
+        {
+            ProjectId = command.ProjectId,
+            UserId = request.UserId,
+            Role = role,
+        };
+
+        uow.Projects.AddMember(member);
+        uow.Projects.AddMemberPermission(new ProjectMemberPermission
+        {
+            ProjectId = command.ProjectId,
+            UserId = request.UserId,
+            Screen = ProjectPermissionScreens.Documents,
+            CanView = true,
+            CanCreate = role == MemberRole.Owner,
+            CanEdit = role == MemberRole.Owner,
+            CanDelete = role == MemberRole.Owner,
+        });
+        await uow.SaveChangesAsync(ct);
+
+        return new ProjectMemberDto
+        {
+            UserId = user.Id,
+            Username = user.Username,
+            DisplayName = user.DisplayName,
+            Role = member.Role,
+            CanViewDocuments = true,
+            CanCreateDocuments = role == MemberRole.Owner,
+            CanEditDocuments = role == MemberRole.Owner,
+            CanDeleteDocuments = role == MemberRole.Owner,
+        };
+    }
+}

mws.application/Projects/Commands/RemoveProjectMember.cs

@@ -0,0 +1,31 @@
+using MediatR;
+using Mws.Application.Common;
+using Mws.Domain.Projects;
+
+namespace Mws.Application.Projects;
+
+public record RemoveProjectMemberCommand(Guid UserId, Guid ProjectId, Guid MemberUserId) : IRequest;
+
+public class RemoveProjectMemberHandler(IUnitOfWork uow) : IRequestHandler<RemoveProjectMemberCommand>
+{
+    public async Task Handle(RemoveProjectMemberCommand command, CancellationToken ct)
+    {
+        if (await uow.Projects.GetMemberRoleAsync(command.ProjectId, command.UserId, ct) != MemberRole.Owner)
+        {
+            throw new ForbiddenException("Only the project owner can remove members");
+        }
+
+        var member = await uow.Projects.GetMemberAsync(command.ProjectId, command.MemberUserId, ct)
+            ?? throw new NotFoundException("Member not found in project");
+
+        var owners = await uow.Projects.CountOwnersAsync(command.ProjectId, ct);
+
+        if (member.Role == MemberRole.Owner && owners <= 1)
+        {
+            throw new BadRequestException("Cannot remove the last owner of the project");
+        }
+
+        uow.Projects.RemoveMember(member);
+        await uow.SaveChangesAsync(ct);
+    }
+}

mws.application/Projects/Commands/UpdateMemberDocumentPermissions.cs

@@ -0,0 +1,54 @@
+using MediatR;
+using Mws.Application.Common;
+using Mws.Domain.Projects;
+
+namespace Mws.Application.Projects;
+
+public record UpdateMemberDocumentPermissionsCommand(
+    Guid UserId, Guid ProjectId, Guid MemberUserId, UpdateMemberDocumentPermissionsRequest Request) : IRequest<ProjectMemberDto>;
+
+public class UpdateMemberDocumentPermissionsHandler(IUnitOfWork uow)
+    : IRequestHandler<UpdateMemberDocumentPermissionsCommand, ProjectMemberDto>
+{
+    public async Task<ProjectMemberDto> Handle(UpdateMemberDocumentPermissionsCommand command, CancellationToken ct)
+    {
+        if (await uow.Projects.GetMemberRoleAsync(command.ProjectId, command.UserId, ct) != MemberRole.Owner)
+        {
+            throw new ForbiddenException("Only the project owner can change member permissions");
+        }
+
+        var member = await uow.Projects.GetMemberWithUserAsync(command.ProjectId, command.MemberUserId, ct)
+            ?? throw new NotFoundException("Member not found in project");
+
+        if (member.Role == MemberRole.Owner)
+        {
+            throw new BadRequestException("Owner permissions cannot be changed");
+        }
+
+        var permission = await uow.Projects.GetMemberPermissionAsync(command.ProjectId, command.MemberUserId, ProjectPermissionScreens.Documents, ct);
+        if (permission is null)
+        {
+            permission = new ProjectMemberPermission { ProjectId = command.ProjectId, UserId = command.MemberUserId, Screen = ProjectPermissionScreens.Documents };
+            uow.Projects.AddMemberPermission(permission);
+        }
+
+        var request = command.Request;
+        permission.CanView = request.CanViewDocuments;
+        permission.CanCreate = request.CanCreateDocuments;
+        permission.CanEdit = request.CanEditDocuments;
+        permission.CanDelete = request.CanDeleteDocuments;
+        await uow.SaveChangesAsync(ct);
+
+        return new ProjectMemberDto
+        {
+            UserId = member.UserId,
+            Username = member.User.Username,
+            DisplayName = member.User.DisplayName,
+            Role = member.Role,
+            CanViewDocuments = permission.CanView,
+            CanCreateDocuments = permission.CanCreate,
+            CanEditDocuments = permission.CanEdit,
+            CanDeleteDocuments = permission.CanDelete,
+        };
+    }
+}