feat(load-index): populate battle_pass_level_info from IBattlePassService

Wire IBattlePassService.GetLevelCurveAsync into LoadController so /load/index
emits the 100-entry battle_pass_level_info dict when levels are seeded.

Also adds BattlePassRepository.ResetLevelCurveCache() to bust the process-level
static cache in tests that seed levels after earlier HTTP calls have primed it
with an empty list, and updates SVSimTestFactory.SeedGlobalsAsync + the stale
Index_surfaces_seeded_globals_after_bootstrap assertion accordingly.

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

SVSim.Database/Repositories/BattlePass/BattlePassRepository.cs

@@ -50,4 +50,11 @@ public sealed class BattlePassRepository : IBattlePassRepository
         }
         finally { _curveCacheLock.Release(); }
     }
+
+    /// <summary>
+    /// Drops the process-level level-curve cache. Tests that seed BattlePassLevels after the
+    /// cache has already been populated (by an earlier test's HTTP call) must call this before
+    /// re-seeding so the next read fetches fresh rows.
+    /// </summary>
+    public static void ResetLevelCurveCache() => _curveCache = null;
 }