feat(emblem): /emblem/emblem_list returns owned ids

SVSim.EmulatedEntrypoint/Controllers/EmblemController.cs

@@ -0,0 +1,39 @@
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.EntityFrameworkCore;
+using SVSim.Database;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Common;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Requests;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Responses.Emblem;
+
+namespace SVSim.EmulatedEntrypoint.Controllers;
+
+/// <summary>
+/// /emblem/* — viewer-scoped emblem (lobby/profile badge) management. Read, mark-favorite,
+/// set-currently-displayed. Mirrors /sleeve/* and /degree/*.
+/// </summary>
+[Route("emblem")]
+public class EmblemController : SVSimController
+{
+    private readonly SVSimDbContext _db;
+
+    public EmblemController(SVSimDbContext db) => _db = db;
+
+    [HttpPost("emblem_list")]
+    public async Task<ActionResult<EmblemListResponse>> EmblemList(BaseRequest _, CancellationToken ct)
+    {
+        if (!TryGetViewerId(out long viewerId)) return Unauthorized();
+
+        var viewer = await _db.Viewers
+            .Include(v => v.Emblems)
+            .FirstOrDefaultAsync(v => v.Id == viewerId, ct);
+        if (viewer is null) return Unauthorized();
+
+        return new EmblemListResponse
+        {
+            UserEmblemList = viewer.Emblems
+                .Select(e => new EmblemListEntry { EmblemId = e.Id })
+                .OrderBy(x => x.EmblemId)
+                .ToList(),
+        };
+    }
+}