feedback5 CB5: a 调度中心 upgrade opens the new level's extra slot at once with a new card, the cards shown stay in place (community report of 2026-10-06, item 19; the official tutorial's 休整期 page: 「升级后将出现更多的商品栏位」)

Until 0.2.0 the shop kept its old slot count until the next roll (a refresh or the round start), so a
level-up 1→2 (险境: 3→4 operator slots) or 3→4 (4→5; 标准: 5→6) showed no new card.
PlayerState._openLevelSlots (player/economy.js): the extra slots of the new level are appended to the
chess slots (the item slot stays after them), each drawn at the new level; [ASSUMED] the new card follows
the freeze toggle as a manual refresh's cards do. audit.js checks the slot count and that every card
shown before stays in place. Docs: META.md §3 / §7, PLAYING.md.

Golden: matches — all 18 scenarios moved (solo-FUNNY-1/2, solo-NORMAL-1/2, solo-HARD-1/2, solo-ABYSS-1/2,
coop2-NORMAL-3, coop2-HARD-4, coop3-ABYSS-5, coop4-FUNNY-6, coop4-ABYSS-7, coop2-NORMAL-8-serverrun,
solo-HARD-9-boosted, coop2-ABYSS-10-boosted, coop2-NORMAL-14-standins, coop2-NORMAL-70-diy): every bot
levels its shop and now sees (and draws the shop RNG for) the new card at once, so purchases and boards
part from there. roster / bonds / fields / standins / diy unchanged; no engine error stored.
Tests: test/match/feedback5-shop-levelslots.test.js (new).

docs/META.md

@@ -505,7 +505,8 @@ Any `choice:` handler whose EffectRef reuses its own key must guard like this (o
   items by `price`, refresh 1 (free refreshes first), sell +1 (elite too; items cannot be sold, only destroyed).
 * **Shop**: `shopSlots[level]` chess slots + item slot(s), copy-weighted rolls over remaining pool copies of unbanned,
   visible chess with tier ≤ level; item slot: tier by the same shares, uniform item within the tier. Level-up price =
-  base per mode, −1 each round start (floor 0), reset to the next base after upgrading; `MAX_LEVEL` at 6. One freeze
+  base per mode, −1 each round start (floor 0), reset to the next base after upgrading; an upgrade opens the new level's
+  extra slots at once with new cards (the cards shown stay); `MAX_LEVEL` at 6. One freeze
   toggle freezes every unsold slot until the next round start; a manual refresh rerolls everything (new slots stay
   frozen). Unfrozen slots are cleared at combat start. Slot positions are stable (frozen slots keep their index).
 * **Pool**: copies 12/14/18/16/8/5 (缪尔赛思 4); a normal piece holds 1 copy, an elite 3; displays never reserve copies;
@@ -823,7 +824,9 @@ round was over. The official 1 s `broadcastBeginDelay` is not modelled.
   units > active bond > Σ active layers > standing > seat; the ranks marked 存疑 in PRTS). Unite enemies re-enter with
   their original stats on the official 联防 spawn timing (waves.js `buildUniteWave`, DATA.md §15 #22).
 * A manual refresh while frozen keeps the new slots frozen until the next round start.
-* Level-up does not add slots until the next roll (refresh / round start).
+* A level-up opens the new level's extra slots at once, each with a new card drawn at the new level, and keeps the
+  cards shown (0.2.0, community report item 19; the official tutorial's 「升级后将出现更多的商品栏位」); the new card
+  follows the freeze toggle like a manual refresh's cards.
 * Buying a second copy of an equipped normal item merges into the golden item in the hand (not equipped).
 * Promotions by effects (升华, 博士投影) keep the equipment; merges return it; 突变细胞's transformation returns it (the
   cell included) before its new operator is gained into the 整备区 — the carrier's tile is left empty (official footage,