Practice/deck editing mostly there

SVSim.EmulatedEntrypoint/Controllers/ConfigController.cs

@@ -0,0 +1,31 @@
+using Microsoft.AspNetCore.Mvc;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Common;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Requests;
+
+namespace SVSim.EmulatedEntrypoint.Controllers;
+
+/// <summary>
+/// /config/* — viewer-scoped preference toggles. Fired by the client as fire-and-forget
+/// after the deck-builder save flow (and from settings screens). Currently acknowledge-only:
+/// UserConfig is stubbed in load/index + mypage/index until a viewer-config persistence
+/// layer lands. Mirrors the set_deck_redis precedent (no-op accept).
+/// </summary>
+public class ConfigController : SVSimController
+{
+    [HttpPost("update_foil_preferred")]
+    public ActionResult<EmptyResponse> UpdateFoilPreferred(ConfigUpdateFoilPreferredRequest request)
+    {
+        if (!TryGetViewerId(out long _)) return Unauthorized();
+        // TODO(viewer-config-persist): write request.IsFoilPreferred onto the viewer's config row
+        // and read it back in load/index + mypage/index instead of `new UserConfig()`.
+        return new EmptyResponse();
+    }
+
+    [HttpPost("update_prize_preferred")]
+    public ActionResult<EmptyResponse> UpdatePrizePreferred(ConfigUpdatePrizePreferredRequest request)
+    {
+        if (!TryGetViewerId(out long _)) return Unauthorized();
+        // TODO(viewer-config-persist): see UpdateFoilPreferred.
+        return new EmptyResponse();
+    }
+}