二七王：出牌顺序收敛为唯一口径，重连包补发 baozhu

同一份数据「这一手打出的牌」此前有两个顺序口径：chupai*/playproc.cards
回显客户端请求原序，重连包 pushlist 则从 playround 反查后自己再排一次序。
一手多张（甩牌/对子/拖拉机）时两者必然分岔；同编码的一对牌更是排序都
区分不了，靠"两处各自排序"永远收敛不了。

改为单一写入处：
- 新增 order_playcards()，do_playcard 入口归一化一次（顺带隔离
  can_playcard 的原地排序，不再就地改写 pack.data.cards）
- 新增 paiju.playhistory，出牌当场归档；新增 get_pushlist() 只做深拷贝
- class.export.js 删掉整段反查+重排，改为直读归档
- do_playcard 三个分支都给 re.cards，mod.js 去掉回落到入参的兜底

顺带修复重连包漏发 baozhu：它是余主公示与明牌按钮的开关，此前只在
chupai 包里给，报无主后重连按钮会凭空消失。现与 chupai 同源同门控下发。

协议文档新增 §0.6「一手出牌」的顺序口径，并补 PushCards.baozhu 字段。
测试：pushlist 一节改为真实链路驱动（一手多张 + 乱序提交），断言升级为
「重连每一手与当时的 chupai.cards 逐元素相等」；三处修复均已退回验证转红。

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

server/games/erqiwang/test/test_paiju.js

@@ -128,7 +128,7 @@ function mkBottomPaiju(maxseat, winCards, bottomScoreCards, flower) {
     for (let i = 0; i < 108; i++) cards[i] = { id: i, playround: -1, score: 0, dealowner: 1, playowner: -1 };
     for (const [cid, sc] of bottomScoreCards) { cards[cid].playround = 0; cards[cid].score = sc; }
     const pc = [[], [], []]; pc[maxseat] = winCards;
-    const o = { banker: 0, flower, cards, playproc: { maxseat, cards: pc } };
+    const o = { banker: 0, flower, cards, playproc: { maxseat, cards: pc }, playhistory: [] };
     o.method = { get_burycard: () => P.get_burycard(o), get_grade_incard: c => P.get_grade_incard(o, c) };
     return o;
 }
@@ -154,7 +154,7 @@ function mkFirstPlay(flower, dealMap) {
     for (let i = 0; i < 108; i++) cards[i] = { id: i, dealowner: 99, playround: -1, playowner: -1, score: 0, flower: A.id_to_flower(i), number: A.id_to_number(i) };
     for (const [cid, owner] of dealMap) cards[cid].dealowner = owner;
     const sl = () => [[0, 0], [0, 0], [0, 0], [0, 0], [-1, -1]];
-    const o = { step: 5, banker: 0, flower, cards, seatlist: [sl(), sl(), sl()], playproc: {} };
+    const o = { step: 5, banker: 0, flower, cards, seatlist: [sl(), sl(), sl()], playproc: {}, playhistory: [] };
     o.method = { have_baofu: () => o.seatlist.some(s => s[4][0] == 0) };
     P.new_playround(o, 1, 0);
     return o;
@@ -193,7 +193,7 @@ function mkTrick(deal, scores) {
     for (const [cid, seat] of deal) cards[cid].dealowner = seat + 1;
     for (const [cid, s] of scores) cards[cid].score = s;
     const sl = () => [[0, 0], [0, 0], [0, 0], [0, 0], [-1, -1]];
-    const o = { step: 5, banker: 0, flower: 1, cards, seatlist: [sl(), sl(), sl()], playproc: {} };
+    const o = { step: 5, banker: 0, flower: 1, cards, seatlist: [sl(), sl(), sl()], playproc: {}, playhistory: [] };
     o.method = { have_baofu: () => o.seatlist.some(s => s[4][0] == 0) };
     P.new_playround(o, 1, 0);   // 第 1 轮由庄家(0)首出
     return o;