feedback7 R22-LATE: a 画卷 copy that completes a three-copy merge copies the target's equipment again; golden: unchanged

GitHub #389 / PR #390 by @Xinglan233 (this commit is substantially the PR: the snapshot and its test file, ported).
onArt read target.items after grantChess; a gain that completes a merge runs _mergeChess first, which consumes the
target and empties its items, so the copy loop ran on an empty list (two base 维式重锤 never became the +25% one).
The item ids are now recorded before the gain.

Added on top of the PR: after a promotion the copied items are never equipped onto the elite (an already-advanced
item used to go straight back onto it via equipDirect). The promotion unequips the copies (PRTS 帮助 自动卸除 on
合并) and the 画卷 note says the obtained equipment arrives unequipped, so they wait in the hand; a copied normal item
merges with the returned original as before. The non-promotion path is unchanged.

Tests: test/match/scroll-copy-merge.test.js (8; 4 fail on the parent, the advanced-item case also fails with the
PR's snapshot alone). Golden unchanged (no scenario casts 画卷 into a promotion).

server/sim/content/items/meta.js

@@ -119,17 +119,23 @@ export function registerMeta(registry) {
   // 画卷 — trap_copy_front_char: copy the operator in range (elite status included) with its equipment. A copied
   // normal item that completes a pair with an owned one merges at once and the golden stays in the hand (research 04
   // addendum "两个同名道具（无论是否被装备）会自动合并…并自动返回整备区"); the built-in equipped that golden on the copy.
+  // A copy that completes a three-copy merge (GitHub #389, PR #390): the elite wears nothing — the promotion returns the
+  // copies' equipment to the hand (PRTS 帮助 "在失去该干员（…合并等）…时自动卸除") — and the copied items stay in the hand
+  // too (PRTS 画卷 备注 "获得的装备为未装备状态"), a copied normal item merging with the returned original.
   wrap(registry, 'chess_item_6_02_m', () => ({
     onArt(ctx, ev) {
       const target = (ev.targets || []).find((p) => p && p.kind === 'chess');
       if (!target) { ev.error = 'BAD_TARGET'; ev.detail = 'no operator in range'; return; }
+      // snapshot before the gain: a gain that completes a merge consumes the target and empties `target.items`, and an
+      // item merge detaches the original's copy from `target.items` while we iterate (the built-in's live loop then
+      // skipped the next item)
+      const itemIds = (target.items || []).map((it) => it.id);
       const copy = ctx.grantChess(target.id, { requirePool: false, source: 'item:chess_item_6_02_m' });
       if (!copy) { ev.error = 'HAND_FULL'; return; }
-      // snapshot first: a merge detaches the original's copy of the item from `target.items` while we iterate
-      // (the built-in's live loop then skipped the next item)
-      for (const itemId of (target.items || []).map((it) => it.id)) {
+      const promoted = copy.id !== target.id;
+      for (const itemId of itemIds) {
         const got = ctx.grantItem(itemId, { source: 'item:chess_item_6_02_m' });
-        const holder = got ? ctx.piece(copy.uid) : null;
+        const holder = got && !promoted ? ctx.piece(copy.uid) : null;
         if (got && got.id === itemId && holder && holder.kind === 'chess') ctx.equipDirect(got.uid, holder.uid);
       }
     },