fix: call SetKnownOppRack after PrepareSim to prevent clearing

PrepareSim() was clearing knownOppRack to nil, so we need to call
SetKnownOppRack AFTER PrepareSim, not before. This fixes the bug where
the analyzer was not actually using the known opponent rack even though
it logged that it was.

Verified that the PEG solver does not have this issue - it does not
clear knownOppRack in its Init or Solve methods.

Also cleaned up excessive debug logging.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: domino14

gameanalysis/analyzer.go

@@ -173,6 +173,9 @@ func (a *Analyzer) AnalyzeSingleTurn(ctx context.Context, history *pb.GameHistor
 				if int(phonyPlayEvent.PlayerIndex) != playerIndex {
 					// Opponent's phony was challenged off, we know their rack
 					knownOppRack = extractExposedTiles(prevEvent.PlayedTiles, g.Alphabet())
+					log.Info().
+						Str("exposedTiles", prevEvent.PlayedTiles).
+						Msg("extracted known opponent rack from challenged phony")
 				}
 			}
 		}
@@ -578,7 +581,13 @@ func (a *Analyzer) analyzeWithSim(ctx context.Context, g *game.Game, analysis *T
 		simmer.SetThreads(a.analysisCfg.Threads)
 	}
 
-	// Set known opponent rack if available
+	// Prepare simulation
+	err = simmer.PrepareSim(plies, plays)
+	if err != nil {
+		return fmt.Errorf("failed to prepare simulation: %w", err)
+	}
+
+	// Set known opponent rack if available (MUST be after PrepareSim which clears it)
 	if len(knownOppRack) > 0 {
 		simmer.SetKnownOppRack(knownOppRack)
 		analysis.KnownOppRack = tilemapping.MachineWord(knownOppRack).UserVisible(g.Alphabet())
@@ -587,12 +596,6 @@ func (a *Analyzer) analyzeWithSim(ctx context.Context, g *game.Game, analysis *T
 			Msg("analyzing with known opponent rack from challenged phony")
 	}
 
-	// Prepare simulation
-	err = simmer.PrepareSim(plies, plays)
-	if err != nil {
-		return fmt.Errorf("failed to prepare simulation: %w", err)
-	}
-
 	// Ensure the played move is simmed (avoid pruning it)
 	simmer.AvoidPruningMoves([]*move.Move{analysis.PlayedMove})