feat(game): 添加局间结算界面，对接后端settlement状态

- GameState新增currentRound/totalRounds字段
- 解析后端返回的current_round和total_rounds
- 新增结算弹窗：展示每位玩家得分、胡牌标记和排名
- 状态面板显示当前局数信息
- 新增next_round动作，结算后点击"下一局"继续游戏
- 最后一局结算后显示"返回大厅"按钮

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

src/assets/styles/room.css

@@ -1616,3 +1616,157 @@
     font-size: 18px;
   }
 }
+
+/* ── Settlement Overlay ── */
+.settlement-overlay {
+  position: absolute;
+  inset: 0;
+  z-index: 100;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: rgba(0, 0, 0, 0.65);
+  backdrop-filter: blur(4px);
+  animation: settlement-fade-in 300ms ease-out;
+}
+
+@keyframes settlement-fade-in {
+  from { opacity: 0; }
+  to { opacity: 1; }
+}
+
+.settlement-panel {
+  width: 380px;
+  max-width: 90vw;
+  padding: 28px 24px 20px;
+  border: 1px solid rgba(220, 191, 118, 0.3);
+  border-radius: 16px;
+  background:
+    linear-gradient(180deg, rgba(14, 55, 40, 0.96), rgba(8, 36, 27, 0.98)),
+    radial-gradient(circle at 20% 24%, rgba(237, 214, 157, 0.06), transparent 34%);
+  box-shadow:
+    inset 0 1px 0 rgba(255, 244, 214, 0.08),
+    0 24px 48px rgba(0, 0, 0, 0.4);
+  animation: settlement-panel-pop 300ms ease-out;
+}
+
+@keyframes settlement-panel-pop {
+  from { opacity: 0; transform: scale(0.92) translateY(12px); }
+  to { opacity: 1; transform: scale(1) translateY(0); }
+}
+
+.settlement-title {
+  margin: 0 0 4px;
+  color: #e5c472;
+  font-size: 20px;
+  font-weight: 800;
+  text-align: center;
+  letter-spacing: 1px;
+  text-shadow:
+    -1px 0 rgba(0, 0, 0, 0.38),
+    0 1px rgba(0, 0, 0, 0.38),
+    1px 0 rgba(0, 0, 0, 0.38),
+    0 -1px rgba(0, 0, 0, 0.38);
+}
+
+.settlement-round-info {
+  margin: 0 0 16px;
+  color: rgba(229, 196, 114, 0.6);
+  font-size: 13px;
+  text-align: center;
+  letter-spacing: 0.5px;
+}
+
+.settlement-list {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+  margin-bottom: 20px;
+}
+
+.settlement-row {
+  display: flex;
+  align-items: center;
+  gap: 10px;
+  padding: 10px 14px;
+  border-radius: 10px;
+  background: rgba(255, 255, 255, 0.04);
+  transition: background 150ms;
+}
+
+.settlement-row.is-winner {
+  background: rgba(229, 196, 114, 0.1);
+  border: 1px solid rgba(220, 191, 118, 0.2);
+}
+
+.settlement-row.is-self {
+  box-shadow: inset 0 0 0 1px rgba(229, 196, 114, 0.18);
+}
+
+.settlement-rank {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 24px;
+  height: 24px;
+  border-radius: 50%;
+  background: rgba(255, 255, 255, 0.08);
+  color: rgba(255, 255, 255, 0.7);
+  font-size: 12px;
+  font-weight: 700;
+  flex-shrink: 0;
+}
+
+.settlement-row.is-winner .settlement-rank {
+  background: rgba(229, 196, 114, 0.2);
+  color: #e5c472;
+}
+
+.settlement-name {
+  flex: 1;
+  color: rgba(255, 255, 255, 0.88);
+  font-size: 15px;
+  font-weight: 600;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.settlement-winner-badge {
+  display: inline-block;
+  margin-left: 6px;
+  padding: 1px 6px;
+  border-radius: 4px;
+  background: rgba(229, 196, 114, 0.22);
+  color: #e5c472;
+  font-size: 11px;
+  font-weight: 800;
+  vertical-align: middle;
+}
+
+.settlement-score {
+  font-size: 18px;
+  font-weight: 800;
+  color: rgba(255, 255, 255, 0.7);
+  flex-shrink: 0;
+  min-width: 48px;
+  text-align: right;
+}
+
+.settlement-score.is-positive {
+  color: #5dda6e;
+}
+
+.settlement-score.is-negative {
+  color: #e85d5d;
+}
+
+.settlement-actions {
+  display: flex;
+  justify-content: center;
+  gap: 12px;
+}
+
+.settlement-btn {
+  min-width: 160px;
+}