feat: 实现最小正式版过水不胡规则并完善前端动作面板

- 后端实现最小正式版过水不胡规则：玩家在响应窗口选择PASS后，直到下次摸牌前不能响应胡
- 完善GameSeat状态管理，新增passedHuBlocked字段及相关方法
- 在ResponseActionWindowBuilder和GameActionProcessor中增加过水不胡校验
- 前端重构动作面板，区分回合动作和响应动作，支持多用户视角切换
- 优化公共事件处理逻辑，自动清理失效的私有动作面板
- 更新相关文档说明当前实现的规则范围和工程取舍
- 补充测试用例验证过水不胡规则的正确性

backend/src/main/java/com/xuezhanmaster/game/domain/GameSeat.java

@@ -16,6 +16,8 @@ public class GameSeat {
     private TileSuit lackSuit;
     private boolean won;
     private int score;
+    // 过水不胡最小版：只限制“响应胡”，直到该玩家下一次摸牌后解除；不影响自摸胡。
+    private boolean passedHuBlocked;
 
     public GameSeat(int seatNo, boolean ai, String nickname) {
         this(seatNo, ai, UUID.randomUUID().toString(), nickname);
@@ -76,10 +78,22 @@ public class GameSeat {
         return score;
     }
 
+    public boolean isPassedHuBlocked() {
+        return passedHuBlocked;
+    }
+
     public void addScore(int delta) {
         this.score += delta;
     }
 
+    public void markPassedHuBlocked() {
+        this.passedHuBlocked = true;
+    }
+
+    public void clearPassedHuBlocked() {
+        this.passedHuBlocked = false;
+    }
+
     public void receiveTile(Tile tile) {
         handTiles.add(tile);
     }

backend/src/main/java/com/xuezhanmaster/game/service/GameActionProcessor.java

@@ -287,6 +287,14 @@ public class GameActionProcessor {
                 .findFirst()
                 .orElseThrow(() -> new BusinessException("GAME_ACTION_WINDOW_INVALID", "当前玩家不在" + actionName + "响应候选中"));
 
+        if ("胡".equals(actionName) && actorSeat.isPassedHuBlocked()) {
+            boolean hasHuOption = seatCandidate.options().stream()
+                    .anyMatch(option -> option.actionType() == ActionType.HU);
+            if (!hasHuOption) {
+                throw new BusinessException("GAME_ACTION_WINDOW_INVALID", "当前处于过水不胡限制中，需待下次摸牌后才能再胡");
+            }
+        }
+
         boolean matched = seatCandidate.options().stream()
                 .anyMatch(option -> option.actionType().name().equals(toActionTypeName(actionName))
                         && (tileDisplayName == null || tileDisplayName.equals(option.tile())));

backend/src/main/java/com/xuezhanmaster/game/service/GameSessionService.java

@@ -180,6 +180,8 @@ public class GameSessionService {
         GameSeat nextSeat = nextSeatOptional.get();
         Tile drawnTile = table.getWallTiles().remove(0);
         nextSeat.receiveTile(drawnTile);
+        // 玩家真正完成下一次摸牌后，才解除此前由“过水不胡”带来的响应胡限制。
+        nextSeat.clearPassedHuBlocked();
         table.setCurrentSeatNo(nextSeat.getSeatNo());
         gameMessagePublisher.publishPublicEvent(GameEvent.tileDrawn(session.getGameId(), nextSeat.getSeatNo(), table.getWallTiles().size()));
         gameMessagePublisher.publishPublicEvent(GameEvent.turnSwitched(session.getGameId(), nextSeat.getSeatNo()));
@@ -366,6 +368,7 @@ public class GameSessionService {
     private void handlePassPostAction(GameSession session, GameActionRequest request) {
         ResponseActionWindow responseActionWindow = requirePendingResponseWindow(session);
         GameSeat actorSeat = findSeatByUserId(session.getTable(), request.userId());
+        markPassedHuBlockedIfNeeded(responseActionWindow, actorSeat);
         session.getResponseActionSelections().put(actorSeat.getSeatNo(), ActionType.PASS);
         tryResolveResponseWindow(session, responseActionWindow);
     }
@@ -413,6 +416,7 @@ public class GameSessionService {
         for (ResponseActionSeatCandidate seatCandidate : responseActionWindow.seatCandidates()) {
             GameSeat seat = session.getTable().getSeats().get(seatCandidate.seatNo());
             if (seat.isAi()) {
+                markPassedHuBlockedIfNeeded(responseActionWindow, seat);
                 session.getResponseActionSelections().put(seatCandidate.seatNo(), ActionType.PASS);
             }
         }
@@ -590,6 +594,7 @@ public class GameSessionService {
 
         Tile drawnTile = table.getWallTiles().remove(0);
         winnerSeat.receiveTile(drawnTile);
+        winnerSeat.clearPassedHuBlocked();
         markPostGangContext(session, winnerSeat.getSeatNo(), claimedTile.getDisplayName());
         appendAndPublish(session, GameEvent.tileDrawn(session.getGameId(), winnerSeat.getSeatNo(), table.getWallTiles().size()));
         appendAndPublish(session, GameEvent.turnSwitched(session.getGameId(), winnerSeat.getSeatNo()));
@@ -726,6 +731,7 @@ public class GameSessionService {
 
         Tile drawnTile = table.getWallTiles().remove(0);
         winnerSeat.receiveTile(drawnTile);
+        winnerSeat.clearPassedHuBlocked();
         markPostGangContext(session, winnerSeat.getSeatNo(), gangTile.getDisplayName());
         appendAndPublish(session, GameEvent.tileDrawn(session.getGameId(), winnerSeat.getSeatNo(), table.getWallTiles().size()));
         appendAndPublish(session, GameEvent.turnSwitched(session.getGameId(), winnerSeat.getSeatNo()));
@@ -786,12 +792,21 @@ public class GameSessionService {
 
         Tile drawnTile = table.getWallTiles().remove(0);
         winnerSeat.receiveTile(drawnTile);
+        winnerSeat.clearPassedHuBlocked();
         markPostGangContext(session, winnerSeat.getSeatNo(), gangTile.getDisplayName());
         appendAndPublish(session, GameEvent.tileDrawn(session.getGameId(), winnerSeat.getSeatNo(), table.getWallTiles().size()));
         appendAndPublish(session, GameEvent.turnSwitched(session.getGameId(), winnerSeat.getSeatNo()));
         continueFromResolvedActionTurn(session, winnerSeat);
     }
 
+    private void markPassedHuBlockedIfNeeded(ResponseActionWindow responseActionWindow, GameSeat seat) {
+        responseActionWindow.seatCandidates().stream()
+                .filter(candidate -> candidate.seatNo() == seat.getSeatNo())
+                .findFirst()
+                .filter(candidate -> candidate.options().stream().anyMatch(option -> option.actionType() == ActionType.HU))
+                .ifPresent(candidate -> seat.markPassedHuBlocked());
+    }
+
     private ActionType parseActionType(String actionType) {
         try {
             return ActionType.valueOf(actionType.toUpperCase(Locale.ROOT));

backend/src/main/java/com/xuezhanmaster/game/service/ResponseActionWindowBuilder.java

@@ -63,7 +63,8 @@ public class ResponseActionWindowBuilder {
             if (seat.getSeatNo() == sourceSeatNo || seat.isWon()) {
                 continue;
             }
-            if (!huEvaluator.canHuWithClaimedTile(seat.getHandTiles(), gangTile)) {
+            // 抢杠胡也属于“响应胡”，因此同样受过水不胡限制。
+            if (!canHuByResponse(seat, gangTile)) {
                 continue;
             }
             seatCandidates.add(new ResponseActionSeatCandidate(
@@ -91,7 +92,8 @@ public class ResponseActionWindowBuilder {
 
     private List<ResponseActionOption> buildSeatOptions(GameSeat seat, Tile discardedTile) {
         int sameTileCount = countSameTileInHand(seat, discardedTile);
-        boolean canHu = huEvaluator.canHuWithClaimedTile(seat.getHandTiles(), discardedTile);
+        // 过水不胡只屏蔽响应胡候选，不影响同窗口内仍可用的碰、杠。
+        boolean canHu = canHuByResponse(seat, discardedTile);
         if (!canHu && sameTileCount < 2) {
             return List.of();
         }
@@ -114,6 +116,13 @@ public class ResponseActionWindowBuilder {
         return options;
     }
 
+    private boolean canHuByResponse(GameSeat seat, Tile triggerTile) {
+        if (seat.isPassedHuBlocked()) {
+            return false;
+        }
+        return huEvaluator.canHuWithClaimedTile(seat.getHandTiles(), triggerTile);
+    }
+
     private int countSameTileInHand(GameSeat seat, Tile discardedTile) {
         int count = 0;
         for (Tile tile : seat.getHandTiles()) {