feat(degree): /degree/degree_list returns owned ids

SVSim.EmulatedEntrypoint/Controllers/DegreeController.cs

@@ -0,0 +1,41 @@
+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.Requests.Degree;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Responses.Degree;
+
+namespace SVSim.EmulatedEntrypoint.Controllers;
+
+/// <summary>
+/// /degree/* — viewer-scoped degree (title) management. Read, mark-favorite, set-currently-displayed.
+/// Mirrors /sleeve/* and /emblem/*; favorite handler is no-op like the others until a viewer-favorites
+/// schema lands (would also serve /sleeve/favorite + /emblem/favorite via the shared Wizard/FavoriteTask.cs Kind enum).
+/// </summary>
+[Route("degree")]
+public class DegreeController : SVSimController
+{
+    private readonly SVSimDbContext _db;
+
+    public DegreeController(SVSimDbContext db) => _db = db;
+
+    [HttpPost("degree_list")]
+    public async Task<ActionResult<DegreeListResponse>> DegreeList(DegreeListRequest _, CancellationToken ct)
+    {
+        if (!TryGetViewerId(out long viewerId)) return Unauthorized();
+
+        var viewer = await _db.Viewers
+            .Include(v => v.Degrees)
+            .FirstOrDefaultAsync(v => v.Id == viewerId, ct);
+        if (viewer is null) return Unauthorized();
+
+        return new DegreeListResponse
+        {
+            UserDegreeList = viewer.Degrees
+                .Select(d => new DegreeListEntry { DegreeId = d.Id })
+                .OrderBy(e => e.DegreeId)
+                .ToList(),
+        };
+    }
+}