Add tip audit logging, CFR alignment tests, and multiway scenarios

Three confidence features for the poker tip system:
- Tip audit table (holdem_tip_audit) logs every tip with full context
  for bulk review after real sessions
- CFR alignment test validates all 32 scenarios against the trained
  5M-iteration policy — rules engine never contradicts the bot's AI
- 8 new multiway test scenarios covering all streets and key decisions

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

internal/plugin/holdem.go

@@ -956,10 +956,12 @@ func (p *HoldemPlugin) sendTurnNotifications(game *HoldemGame) {
 	if actionPlayer.TipsEnabled {
 		snap := snapshotForTip(game, game.ActionIdx)
 		dmRoom := actionPlayer.DMRoomID
+		playerID := string(actionPlayer.UserID)
 		safeGo("holdem-tip", func() {
 			tipCtx := buildTipContext(snap)
 			tip := generateTip(tipCtx)
 			p.SendMessage(dmRoom, tip)
+			logTipAudit(playerID, tipCtx, tip)
 		})
 	}
 }