feat(bp): IBattlePassService skeleton + level-curve method + DI

SVSim.EmulatedEntrypoint/Services/BattlePassPointGrant.cs

@@ -0,0 +1,17 @@
+using SVSim.Database.Services;
+
+namespace SVSim.EmulatedEntrypoint.Services;
+
+/// <summary>
+/// Result of <see cref="IBattlePassService.AddPointsAsync"/>. Future point-source endpoints
+/// (mission/retire, battle finish handlers) translate this into the embedded
+/// <c>battle_pass_gauge_info</c> block on their response.
+/// </summary>
+public sealed record BattlePassPointGrant(
+    int BeforePoint,
+    int BeforeLevel,
+    int AfterPoint,
+    int AfterLevel,
+    int PointAdd,
+    BattlePassPointSource Source,
+    IReadOnlyList<GrantedReward> NewlyClaimed);