0.2.4-dev: round-29 community fixes and the official shared card pool

- Shared card pool and item stock as in the official mode (the owner's request, from the 路标档案馆 video and public notes): solo low-tier exceptions, co-op operators x2, shared item stock with special-item exceptions, normal / advanced occupancy 1 / 2, re-check on buy, 机变 exhaustion, release on consume / destroy / elimination; 整备 never exceeds stock; invariant held <= cap.
- 突袭: one taunt-first reselect right after a revive (the owner's rule); ordinary polls and redeploys keep the 0.2.3 rule; a revive on an enemy's tile stays. #475: online boss / hidden-boss Raid may land on the empty half (owner-limited scope).
- 浊心斯卡蒂 S1 x 坚守 no longer bounce redirected damage, and the two shares conserve the hit (idea of PR #464 by @HappyTanuki).
- Operator fixes adapted from PRs by @Xinglan233 (#459 哈洛德 S2 elemental trigger, #460 涤火杰西卡 shield on the four adjacent tiles, #461 家族徽章 first hit after stealth, #462 松果 S2 regrow per deploy); 克莱门莎 S2 splash 1.1 / 100% ATK and air auto-trigger (#467); 白面 copying 歌蕾蒂娅 / 余 skips the three-member condition (#473, the owner's video).
- 香槟炸弹 is not chosen by friendly auras / heals (PR #468 / #476 by @Siornya); 琳琅诗怀雅 coin balance (PR #450 by @IceCodeNew); Touch prep display (PR #451 by @YinqiMargatroid); lobby header (PR #471 by @YuriRestia); Japanese UI terms (PR #448 by @scutkane).
- AI-only boss countdown grace, render-failure cache / recovery without restarting a battle, device units kept on a same-field re-entry, DIY detail / skill previews, large-text result buttons.
- golden: battle families equal 0.2.3 except diy-135 / diy-136 (克莱门莎); all 18 release matches move through the shared pool, every flip named in docs/history/0.2.4.md §29.12; two coverage scenarios added.

server/match/builtinMeta.js

@@ -143,19 +143,20 @@ const ITEM_HANDLERS = {
     },
   },
   // 拟态物质 「若已拥有至少2名该初始干员，则再获得1名该初始干员；否则随机获得1名同盟约初始干员」: the 否则 is the owned < 2
-  // case only. With 2 copies owned and none left in the pool (an elite holds 3 of a Ⅵ阶's 5) the grant fails and the
-  // item gives nothing (research 06 §7: some effects fail at the copy cap) — it never falls back to a same-bond operator
-  // (GitHub #207).
+  // case only. The original experiment BV1eLXXBqEgF (3:00) distinguishes this item from pool-weighted grants:
+  // it samples eligible operator identities and can grant beyond stock. All obtained copies still occupy the pool.
   use_equip_reward_char_chess: {
     onEquip(ctx, ev) {
       const base = ctx.gd.baseIdOf(ev.target.id);
       const owned = [...ctx.board(), ...ctx.hand(), ...ctx.temp()].filter((p) => p && p.kind === 'chess' && !p.golden && ctx.gd.baseIdOf(p.id) === base).length;
       if (owned >= 2) {
-        if (!ctx.grantChess(base)) toastNothing(ctx, ev, ctx.gd.chess(base)?.name || null);
+        if (!ctx.grantChess(base, { requirePool: false })) toastNothing(ctx, ev);
         return;
       }
-      const id = rollSameBond(ctx, ctx.pieceBonds(ev.target.uid), 6);
-      if (!id || !ctx.grantChess(id)) toastNothing(ctx, ev);
+      const bonds = new Set(ctx.pieceBonds(ev.target.uid));
+      const id = ctx.rollChess({ maxTier: 6, ignoreCounts: true,
+        filter: cid => ctx.gd.chess(cid)?.bonds?.some(b => bonds.has(b)) });
+      if (!id || !ctx.grantChess(id, { requirePool: false })) toastNothing(ctx, ev);
     },
   },
   use_equip_reward_special_goods_char_chess: {
@@ -285,7 +286,8 @@ const EFFECT_HANDLERS = {
       to.giftTicker(ctx.name, p.chessId, ctx.playerId);
     },
   },
-  // 整备: the next purchased item becomes advanced (golden)
+  // 整备: the next purchased item becomes advanced (golden). upgradeItem leaves it normal, and this
+  // charge unspent, when the shared stock has no room for the golden's second copy.
   builtin_next_buy_golden_item: {
     onBuy(ctx, ev) {
       const ref = ctx.source.ref;