feedback1 cell: docs for the 突变细胞 bench rule (DESIGN §21.1 / §20.11 / §21.20, META, PLAYING, DATA, research, CHANGELOG)

- DESIGN §21.1 states the corrected rule with its evidence: bilibili BV1vzyVBuEN9 (上半, about 8:24) and
  BV1Qkw1zMEoR (下半, about 7:25) show the carrier's tile empty at the next prep, one more deployment left
  and the new operator on the bench; the PRTS 备注 is a destroy followed by a gain; PRTS 帮助 sends what a
  player gains to the 手牌区; the closed PR #2 said the same (its merge path not adopted). The WA
  keep-the-tile rule and the carrier-tile merge exception are withdrawn; the bench carrier and the
  hand-and-temp-full case stay [ASSUMED].
- §20.11 / §20.9 no longer count a transformed carrier's tile; §21.20 lists the rule as official;
  §21.25 credits PR #2's bench rule; §6.2 and §6.6 follow; the §21 intro maps it.
- META (bot, ctx.transform, built-ins, merge, notes), PLAYING, DATA (items.json note), research 04
  (addendum 2, implFormula, open question 6) and research 01 row 7 follow.
- One CHANGELOG 0.1.1 line (PR #2 指出).
- docs-consistency pins the docs against the code (no fromKey / returnItems left, the gain through
  acquireChess).

CHANGELOG.md

@@ -41,6 +41,7 @@
 
 - 拉普兰德：获得她之后本回合的首次刷新也会叠叙拉古层数，每名拉普兰德各自计算。
 - 昆图斯的突变细胞不会用完消失：每场战斗后装备者换成高一阶的随机干员，突变细胞和其他装备退回整备区，可以再次配发。
+- 突变细胞换来的新干员和官方一样进入整备区，原来的格子空出来、可放置角色加 1，需要自己重新部署；凑齐同名干员时照常合成精锐（PR #2 指出）。
 - 标准模拟按官方禁用奥术等盟约，卡片和盟约详情标明「本局禁用」。
 - 变形同构体配转职装备时，盟约成员列表和干员卡片算上装备者（标「同构」）。
 - 带奥术法阵时，场上炎佑造成伤害也会使目标失去特殊能力 5 秒；带源石溶剂时炎佑每秒受到 60 点伤害。