feat(bp): AddPointsAsync plumbing + level-cross auto-grant + weekly cap

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

SVSim.EmulatedEntrypoint/Services/IBattlePassService.cs

@@ -5,6 +5,16 @@ namespace SVSim.EmulatedEntrypoint.Services;
 
 public interface IBattlePassService
 {
+    /// <summary>
+    /// Plumbing for future point-source endpoints (mission/retire, battle finish handlers).
+    /// Bumps gauge by min(amount, weekly headroom), auto-grants rewards on every level crossed
+    /// (premium track only when IsPremium), writes claim rows + currency/collection mutations
+    /// via RewardGrantService. Returns delta info for caller to embed in
+    /// battle_pass_gauge_info on its response. No live caller in v1; tested directly.
+    /// </summary>
+    Task<BattlePassPointGrant> AddPointsAsync(
+        long viewerId, BattlePassPointSource source, int amount, CancellationToken ct);
+
     /// <summary>Global level curve as wire-string dictionary; null if no levels seeded.</summary>
     Task<IReadOnlyDictionary<string, BattlePassLevel>?> GetLevelCurveAsync(CancellationToken ct);