Convert Accounts module to MediatR commands/queries

Replaces IAccountService/AccountService with one command/query per
operation, following the pattern set in the Auth module.

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

mws.api/Controllers/AccountsController.cs

@@ -1,3 +1,4 @@
+using MediatR;
 using Microsoft.AspNetCore.Authorization;
 using Microsoft.AspNetCore.Mvc;
 using Mws.Application.Accounts;
@@ -7,37 +8,37 @@ namespace Mws.Api.Controllers;
 [ApiController]
 [Route("api/accounts")]
 [Authorize]
-public class AccountsController(IAccountService accountService) : ControllerBase
+public class AccountsController(ISender sender) : ControllerBase
 {
     [HttpGet]
     public async Task<ActionResult<List<AccountDto>>> GetAll([FromQuery] string? q, CancellationToken ct)
     {
-        return Ok(await accountService.GetAccountsAsync(User.GetUserId(), q, ct));
+        return Ok(await sender.Send(new GetAccountsQuery(User.GetUserId(), q), ct));
     }
 
     [HttpPost]
     public async Task<ActionResult<AccountDto>> Create([FromBody] CreateAccountRequest request, CancellationToken ct)
     {
-        return Ok(await accountService.CreateAccountAsync(User.GetUserId(), request, ct));
+        return Ok(await sender.Send(new CreateAccountCommand(User.GetUserId(), request), ct));
     }
 
     [HttpPut("{id:guid}")]
     public async Task<ActionResult<AccountDto>> Update(Guid id, [FromBody] UpdateAccountRequest request, CancellationToken ct)
     {
-        return Ok(await accountService.UpdateAccountAsync(User.GetUserId(), id, request, ct));
+        return Ok(await sender.Send(new UpdateAccountCommand(User.GetUserId(), id, request), ct));
     }
 
     [HttpDelete("{id:guid}")]
     public async Task<IActionResult> Delete(Guid id, CancellationToken ct)
     {
-        await accountService.DeleteAccountAsync(User.GetUserId(), id, ct);
+        await sender.Send(new DeleteAccountCommand(User.GetUserId(), id), ct);
         return NoContent();
     }
 
     [HttpPost("{id:guid}/reset-password")]
     public async Task<IActionResult> ResetPassword(Guid id, [FromBody] ResetPasswordRequest request, CancellationToken ct)
     {
-        await accountService.ResetPasswordAsync(User.GetUserId(), id, request, ct);
+        await sender.Send(new ResetPasswordCommand(User.GetUserId(), id, request), ct);
         return NoContent();
     }
 }