v0.10.0 fix to engine game state mgmt, client and web ui updates to match

internal/server/service/game.go

@@ -113,7 +113,7 @@ func (s *Service) ApplyMove(gameID, moveUCI, newFEN string) error {
 	g.AddSnapshot(newFEN, moveUCI, nextTurn)
 
 	// Notify waiting clients about the state change
-	s.waiter.NotifyGame(gameID, len(g.Moves()))
+	s.waiter.NotifyGame(gameID, len(g.Moves()), g.State())
 
 	// Persist if storage enabled
 	if s.store != nil {
@@ -132,6 +132,36 @@ func (s *Service) ApplyMove(gameID, moveUCI, newFEN string) error {
 	return nil
 }
 
+// ApplyMoveWithState atomically records a move, its resulting state, and move
+// metadata, then notifies waiters exactly once with the settled state.
+func (s *Service) ApplyMoveWithState(gameID, moveUCI, newFEN string, state core.State, result *game.MoveResult) error {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	g, ok := s.games[gameID]
+	if !ok {
+		return fmt.Errorf("game not found: %s", gameID)
+	}
+
+	currentTurn := g.NextTurnColor()
+	g.AddSnapshot(newFEN, moveUCI, core.OppositeColor(currentTurn))
+	g.SetState(state)
+	if result != nil {
+		g.SetLastResult(result)
+	}
+
+	s.waiter.NotifyGame(gameID, len(g.Moves()), state)
+
+	if s.store != nil {
+		s.store.RecordMove(storage.MoveRecord{
+			GameID: gameID, MoveNumber: len(g.Moves()), MoveUCI: moveUCI,
+			FENAfterMove: newFEN, PlayerColor: currentTurn.String(),
+			MoveTimeUTC: time.Now().UTC(),
+		})
+	}
+	return nil
+}
+
 // UpdateGameState sets the game's end state (checkmate, stalemate, etc)
 func (s *Service) UpdateGameState(gameID string, state core.State) error {
 	s.mu.Lock()
@@ -143,11 +173,8 @@ func (s *Service) UpdateGameState(gameID string, state core.State) error {
 	}
 
 	g.SetState(state)
-
-	// Notify if game ended
-	if state != core.StateOngoing && state != core.StatePending {
-		s.waiter.NotifyGame(gameID, len(g.Moves()))
-	}
+	// Notify unconditionally; the registry decides.
+	s.waiter.NotifyGame(gameID, len(g.Moves()), state)
 
 	return nil
 }
@@ -183,7 +210,7 @@ func (s *Service) UndoMoves(gameID string, count int) error {
 	}
 
 	// Notify waiting clients about the undo
-	s.waiter.NotifyGame(gameID, len(g.Moves()))
+	s.waiter.NotifyGame(gameID, len(g.Moves()), g.State())
 
 	// Delete undone moves from storage if enabled
 	if s.store != nil {
@@ -214,4 +241,5 @@ func (s *Service) DeleteGame(gameID string) error {
 
 	delete(s.games, gameID)
 	return nil
-}
+}
+

internal/server/service/waiter.go

@@ -1,6 +1,7 @@
 package service
 
 import (
+	"chess/internal/server/core"
 	"context"
 	"fmt"
 	"sync"
@@ -84,24 +85,19 @@ func (w *WaitRegistry) RegisterWait(gameID string, moveCount int, ctx context.Co
 }
 
 // NotifyGame notifies all clients waiting on a game about state change
-func (w *WaitRegistry) NotifyGame(gameID string, currentMoveCount int) {
+func (w *WaitRegistry) NotifyGame(gameID string, currentMoveCount int, state core.State) {
 	w.mu.RLock()
 	waitList := w.waiters[gameID]
 	w.mu.RUnlock()
-
 	if len(waitList) == 0 {
 		return
 	}
-
-	// Non-blocking notification to all waiters
+	settled := state != core.StateOngoing && state != core.StatePending
 	for _, req := range waitList {
-		// Only notify if move count changed
-		if req.MoveCount != currentMoveCount {
+		if settled || req.MoveCount != currentMoveCount {
 			select {
 			case req.Notify <- struct{}{}:
-				// Notification sent
 			default:
-				// Channel full or closed, skip slow client
 			}
 		}
 	}
@@ -175,4 +171,3 @@ func (w *WaitRegistry) removeWaiter(gameID string, req *WaitRequest) {
 	// Stop timer if still running
 	req.Timer.Stop()
 }
-