feedback1 cell: a 突变细胞 transformation gains the new operator into the 整备区 and frees the carrier's tile (pointed out in PR #2)

Official gameplay footage (bilibili BV1vzyVBuEN9 at about 8:24, BV1Qkw1zMEoR at about 7:25) shows the
next prep with the carrier's tile empty, one more deployment left, and the returned equipment plus the
new tier+1 operator on the bench, deployed by hand afterwards. That is the PRTS 备注 read as written
("生效时，原干员销毁，获得一名高一阶的随机初始干员"): a destroy followed by a gain. The closed PR #2 made
the same claim from a playtest.

- PlayerState.transformChess: the carrier is destroyed wherever it stands (board tile freed, summons
  removed, copies back to the pool); its equipment, the cell included, returns to the hand first
  (overflow temp, auto-merge); then the new operator is gained through acquireChess like any gained
  operator (hand, overflow temp, the no-room rule of every gain; no summon card until it is deployed).
  The returnItems option is gone (the cell's built-in was its only caller).
- A merge the gain completes merges like any gained copy: the elite takes a consumed deployed copy's
  tile, else the hand. _mergeChess loses fromKey / fromDir, so the destroyed carrier's tile never
  counts (PR #2 had kept that path; not adopted); audit.js drops its exception for it.
- builtinMeta, ctx.transform, items/meta.js and bot.js comments follow. Bots and AI 托管 deploy the
  gained operator in their normal lineup step (no bot change needed; a real co-op round pins it).
- ITEM_RULES note and implFormula for the item card; data/items.json rebuilt with build-data --offline.
- Tests: facing, merge, playtest6-elite-to-board and items no longer pin the kept tile; feedback1-meta
  covers a deployed and a bench carrier, hand full -> temp, hand and temp full, a merge with and
  without a deployed copy (never the carrier's tile), 商业包装方案's count on the returned item, and bots /
  AI 托管 redeploying; feedback1-cell checks the new note.

test/match/facing.test.js

@@ -134,14 +134,16 @@ test('the dir persists across rounds and reaches the round\'s battle', () => {
   m.dispose();
 });
 
-test('effect-placed pieces: a transformation / a merge elite taking a consumed copy\'s tile keep that tile\'s dir', () => {
+test('effect-placed pieces: a transformation leaves the tile (the new operator waits in the hand); a merge elite taking a consumed copy\'s tile keeps that tile\'s dir', () => {
   const { m, ps } = prepMatch({ seed: 13 });
   const [id, other] = meleeIds(m, 2);
   const a = give(m, ps, id, 'board', [9, 3]);
   a.dir = 'DOWN';
   const np = ps.transformChess(a, other);
-  assert.ok(np && ps.board.get(tileKey(9, 3)) === np, 'kept the tile');
-  assert.equal(np.dir, 'DOWN');
+  // 突变细胞 (PRTS 备注 "原干员销毁，获得一名…干员"; official footage, PR #2): the tile is freed, nothing inherits its dir
+  assert.ok(np && !ps.board.has(tileKey(9, 3)), 'the tile is freed');
+  assert.ok(ps.hand.includes(np), 'the new operator waits in the hand');
+  assert.equal(ps.deployCount, 0, 'one deployment fewer');
   // merge of deployed copies (PRTS: the elite goes to the consumed copy's board position), with its dir
   ps.board.clear();
   ps.hand.fill(null);