fix(dto): align daily_login_bonus DTOs with prod wire shape

- numeric fields ship as quoted strings (campaign_id, img, effect_id,
  reward_type, reward_detail_id, reward_number)
- DailyLoginBonus.Campaign is a List<>, not a single object
- LoginBonusCampaign.Img replaces Image (string, asset-key)
- add IsOneDayMultiRewards (SpecialData-only on client, byte-faithful)

SVSim.UnitTests/Dtos/DailyLoginBonusWireShapeTests.cs

@@ -0,0 +1,59 @@
+using System.Text.Json;
+using NUnit.Framework;
+using SVSim.EmulatedEntrypoint.Models.Dtos;
+
+namespace SVSim.UnitTests.Dtos;
+
+public class DailyLoginBonusWireShapeTests
+{
+    private static readonly JsonSerializerOptions Opts = new()
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower,
+        DefaultIgnoreCondition = System.Text.Json.Serialization.JsonIgnoreCondition.WhenWritingNull,
+    };
+
+    [Test]
+    public void Reward_numeric_fields_serialize_as_strings()
+    {
+        var r = new LoginBonusReward
+        {
+            EffectId = "1", RewardType = "9", RewardDetailId = "0", RewardNumber = "20"
+        };
+
+        var json = JsonSerializer.Serialize(r, Opts);
+        using var doc = JsonDocument.Parse(json);
+        Assert.That(doc.RootElement.GetProperty("effect_id").ValueKind,        Is.EqualTo(JsonValueKind.String));
+        Assert.That(doc.RootElement.GetProperty("reward_type").ValueKind,      Is.EqualTo(JsonValueKind.String));
+        Assert.That(doc.RootElement.GetProperty("reward_detail_id").ValueKind, Is.EqualTo(JsonValueKind.String));
+        Assert.That(doc.RootElement.GetProperty("reward_number").ValueKind,    Is.EqualTo(JsonValueKind.String));
+    }
+
+    [Test]
+    public void Campaign_id_and_img_serialize_as_strings()
+    {
+        var c = new LoginBonusCampaign { CampaignId = "3", Img = "0", Name = "Daily Bonus" };
+        var json = JsonSerializer.Serialize(c, Opts);
+        using var doc = JsonDocument.Parse(json);
+        Assert.That(doc.RootElement.GetProperty("campaign_id").ValueKind, Is.EqualTo(JsonValueKind.String));
+        Assert.That(doc.RootElement.GetProperty("img").ValueKind,         Is.EqualTo(JsonValueKind.String));
+    }
+
+    [Test]
+    public void Campaign_supports_is_one_day_multi_rewards_flag()
+    {
+        var c = new LoginBonusCampaign { IsOneDayMultiRewards = false };
+        var json = JsonSerializer.Serialize(c, Opts);
+        using var doc = JsonDocument.Parse(json);
+        Assert.That(doc.RootElement.TryGetProperty("is_one_day_multi_rewards", out var v), Is.True);
+        Assert.That(v.ValueKind, Is.EqualTo(JsonValueKind.False));
+    }
+
+    [Test]
+    public void DailyLoginBonus_campaign_is_an_array()
+    {
+        var d = new DailyLoginBonus { Normal = new LoginBonusCampaign(), Campaign = new List<LoginBonusCampaign>() };
+        var json = JsonSerializer.Serialize(d, Opts);
+        using var doc = JsonDocument.Parse(json);
+        Assert.That(doc.RootElement.GetProperty("campaign").ValueKind, Is.EqualTo(JsonValueKind.Array));
+    }
+}