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

SVSim.EmulatedEntrypoint/Controllers/EmblemController.cs

@@ -3,6 +3,7 @@ using Microsoft.EntityFrameworkCore;
 using SVSim.Database;
 using SVSim.EmulatedEntrypoint.Models.Dtos.Common;
 using SVSim.EmulatedEntrypoint.Models.Dtos.Requests;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Requests.Emblem;
 using SVSim.EmulatedEntrypoint.Models.Dtos.Responses.Emblem;
 
 namespace SVSim.EmulatedEntrypoint.Controllers;
@@ -36,4 +37,14 @@ public class EmblemController : SVSimController
                 .ToList(),
         };
     }
+
+    [HttpPost("favorite")]
+    public ActionResult<EmptyResponse> Favorite([FromBody] EmblemFavoriteRequest _)
+    {
+        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 + /degree/favorite
+        // via the shared Wizard/FavoriteTask.cs Kind enum).
+        return new EmptyResponse();
+    }
 }

SVSim.EmulatedEntrypoint/Models/Dtos/Requests/Emblem/EmblemFavoriteRequest.cs

@@ -0,0 +1,17 @@
+using MessagePack;
+using System.Text.Json.Serialization;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.Requests.Emblem;
+
+[MessagePackObject]
+public class EmblemFavoriteRequest : BaseRequest
+{
+    // Spec note: ids are STRINGS on the wire, not ints. Same gotcha as /sleeve/favorite and /degree/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();
+}

SVSim.UnitTests/Controllers/EmblemControllerFavoriteTests.cs

@@ -0,0 +1,37 @@
+using System.Net;
+using System.Text;
+using NUnit.Framework;
+using SVSim.UnitTests.Infrastructure;
+
+namespace SVSim.UnitTests.Controllers;
+
+public class EmblemControllerFavoriteTests
+{
+    [Test]
+    public async Task Favorite_accepts_add_and_remove_lists()
+    {
+        using var factory = new SVSimTestFactory();
+        long viewerId = await factory.SeedViewerAsync(tutorialState: 0);
+        using var client = factory.CreateAuthenticatedClient(viewerId);
+
+        var requestJson = """{"favorite_add":["100","101"],"favorite_remove":["200"],"viewer_id":"0","steam_id":0,"steam_session_ticket":""}""";
+        var response = await client.PostAsync("/emblem/favorite",
+            new StringContent(requestJson, Encoding.UTF8, "application/json"));
+
+        Assert.That(response.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+    }
+
+    [Test]
+    public async Task Favorite_accepts_empty_lists()
+    {
+        using var factory = new SVSimTestFactory();
+        long viewerId = await factory.SeedViewerAsync(tutorialState: 0);
+        using var client = factory.CreateAuthenticatedClient(viewerId);
+
+        var requestJson = """{"favorite_add":[],"favorite_remove":[],"viewer_id":"0","steam_id":0,"steam_session_ticket":""}""";
+        var response = await client.PostAsync("/emblem/favorite",
+            new StringContent(requestJson, Encoding.UTF8, "application/json"));
+
+        Assert.That(response.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+    }
+}