feat(mission): /mission/receive_reward stub (refresh-only, no decomp)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/Controllers/MissionController.cs

@@ -6,6 +6,7 @@ using SVSim.Database.Repositories.Mission;
 using SVSim.EmulatedEntrypoint.Models.Dtos.Common.Mission;
 using SVSim.EmulatedEntrypoint.Models.Dtos.Mission;
 using SVSim.EmulatedEntrypoint.Models.Dtos.Requests;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Requests.Mission;
 using SVSim.EmulatedEntrypoint.Services;
 
 namespace SVSim.EmulatedEntrypoint.Controllers;
@@ -133,6 +134,22 @@ public class MissionController : SVSimController
         return Ok(dto);
     }
 
+    [HttpPost("receive_reward")]
+    public async Task<IActionResult> ReceiveReward(MissionReceiveRewardRequest _, CancellationToken ct)
+    {
+        if (!TryGetViewerId(out long viewerId)) return Unauthorized();
+
+        // Spec is INFERRED — no decomp task class. Safe stub: refresh MissionInfoDetail
+        // so the client sees its current state. Real reward granting deferred until we
+        // observe a wire call.
+        var viewer = await LoadViewer(viewerId, ct);
+        await _state.EnsureCurrentAsync(viewer.Id, ct);
+        await _db.SaveChangesAsync(ct);
+
+        var dto = await _assembler.BuildAsync(viewer, ct);
+        return Ok(dto);
+    }
+
     private Task<Viewer> LoadViewer(long viewerId, CancellationToken ct) =>
         _db.Viewers
             .Include(v => v.MissionData)

SVSim.EmulatedEntrypoint/Models/Dtos/Requests/Mission/MissionReceiveRewardRequest.cs

@@ -0,0 +1,17 @@
+using MessagePack;
+using System.Text.Json.Serialization;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.Requests.Mission;
+
+/// <summary>
+/// INFERRED shape — the spec at docs/api-spec/endpoints/post-login/mission-receive-reward.md
+/// flags this as not present in the client decompilation. Almost certainly an id of the
+/// mission to claim.
+/// </summary>
+[MessagePackObject]
+public class MissionReceiveRewardRequest : BaseRequest
+{
+    [JsonPropertyName("id")]
+    [Key("id")]
+    public long Id { get; set; }
+}

SVSim.UnitTests/Controllers/MissionControllerReceiveRewardTests.cs

@@ -0,0 +1,26 @@
+using System.Net;
+using System.Text;
+using NUnit.Framework;
+using SVSim.UnitTests.Infrastructure;
+
+namespace SVSim.UnitTests.Controllers;
+
+public class MissionControllerReceiveRewardTests
+{
+    [Test]
+    public async Task ReceiveReward_returns_ok()
+    {
+        using var factory = new SVSimTestFactory();
+        long viewerId = await factory.SeedViewerAsync(tutorialState: 0);
+        using var client = factory.CreateAuthenticatedClient(viewerId);
+
+        // INFERRED: id of the mission to claim. Defensive stub accepts even when
+        // the id doesn't match a current mission — there is no decomp Parse() to
+        // tell us how the server errors.
+        var requestJson = """{"id":1,"viewer_id":"0","steam_id":0,"steam_session_ticket":""}""";
+        var response = await client.PostAsync("/mission/receive_reward",
+            new StringContent(requestJson, Encoding.UTF8, "application/json"));
+
+        Assert.That(response.StatusCode, Is.EqualTo(HttpStatusCode.OK));
+    }
+}