fix(tk2): match original SV (5-battle cap, no loss limit)

User clarified: the 0..7 win reward tiers came from Shadowverse Worlds
Beyond (sequel), not the original game we're emulating. Original SV's
Take Two caps at 5 total battles played and has no loss limit (verified
on prod: queueing continues with 2+ losses).

- arena-two-pick-rewards.json: drop 6w + 7w tiers (12 rows remain).
- ArenaTwoPickConfig: remove MaxLosses property.
- ArenaTwoPickService: termination is now battlesPlayed >= maxBattles
  (5 from MAX(reward.WinCount)). RecordBattleResult no longer flips
  IsSelectCompleted on the 2nd loss.
- ResolveMaxBattleCountAsync empty-catalog default 7 → 5.
- Tests updated for the new counts (16 → 12 rows, max 7 → 5).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.Database/Models/Config/ArenaTwoPickConfig.cs

@@ -10,7 +10,6 @@ public class ArenaTwoPickConfig
 {
     public int RewardScheduleId { get; set; } = 1;
     public int ChallengeId { get; set; } = 1;
-    public int MaxLosses { get; set; } = 2;
     public int ClassXpPerBattle { get; set; } = 100;
     public int SpotPointsPerBattle { get; set; } = 10;