feat(degree): /degree/favorite accept-only (persistence deferred)

SVSim.EmulatedEntrypoint/Controllers/DegreeController.cs

@@ -38,4 +38,14 @@ public class DegreeController : SVSimController
                 .ToList(),
         };
     }
+
+    [HttpPost("favorite")]
+    public ActionResult<EmptyResponse> Favorite([FromBody] DegreeFavoriteRequest _)
+    {
+        if (!TryGetViewerId(out long __)) return Unauthorized();
+        // Accept-and-ack. Persisting per-viewer cosmetic favorites is deferred until
+        // a viewer-favorites schema lands (would also serve /sleeve/favorite + /emblem/favorite
+        // via the shared Wizard/FavoriteTask.cs Kind enum).
+        return new EmptyResponse();
+    }
 }

SVSim.EmulatedEntrypoint/Models/Dtos/Requests/Degree/DegreeFavoriteRequest.cs

@@ -0,0 +1,17 @@
+using MessagePack;
+using System.Text.Json.Serialization;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.Requests.Degree;
+
+[MessagePackObject]
+public class DegreeFavoriteRequest : BaseRequest
+{
+    // Spec note: ids are STRINGS on the wire, not ints. Same gotcha as /sleeve/favorite and /emblem/favorite.
+    [JsonPropertyName("favorite_add")]
+    [Key("favorite_add")]
+    public List<string> FavoriteAdd { get; set; } = new();
+
+    [JsonPropertyName("favorite_remove")]
+    [Key("favorite_remove")]
+    public List<string> FavoriteRemove { get; set; } = new();
+}