feat(missions): /mission/info, /mission/retire, /mission/change_receive_setting

Three endpoints + 9 integration tests. Captured-data-is-catalog: viewer's
achievement Level starts at MIN(Level) per type from the catalog (not 1),
so the assembler always has a row to render against.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/Models/Dtos/Mission/MissionChangeReceiveSettingRequest.cs

@@ -0,0 +1,13 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Requests;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.Mission;
+
+[MessagePackObject]
+public class MissionChangeReceiveSettingRequest : BaseRequest
+{
+    [Key("mission_receive_type")]
+    [JsonPropertyName("mission_receive_type")]
+    public int MissionReceiveType { get; set; }
+}

SVSim.EmulatedEntrypoint/Models/Dtos/Mission/MissionRetireRequest.cs

@@ -0,0 +1,13 @@
+using System.Text.Json.Serialization;
+using MessagePack;
+using SVSim.EmulatedEntrypoint.Models.Dtos.Requests;
+
+namespace SVSim.EmulatedEntrypoint.Models.Dtos.Mission;
+
+[MessagePackObject]
+public class MissionRetireRequest : BaseRequest
+{
+    [Key("id")]
+    [JsonPropertyName("id")]
+    public long Id { get; set; }
+}