feedback5 WE2: effects, reward pools and 机变 cards that grant a random operator also draw the player's 自选 pieces (#9)

「自选干员放入后模拟中的补给池随机范围也将被相应扩大」: player/diy.js diyStockEntries (every
slotted piece with copies left; the roll's own tier rules, no 调度中心 gate) joins
effectsMeta ctx.rollChess / ctx.rollPool (spDraft rollPool extra + chessOf: bonds through
the player's view) and the 驰援 fallback in choices.js. Granted from the player's own
stock (poolOf). Docs: META, PLAYING. Golden: no scenario moved.

server/match/player/diy.js

@@ -25,7 +25,11 @@
 //     shop's chess slots and the reward offers' temporary refreshes [ASSUMED] — weighted like any chess of its tier, once
 //     the 调度中心 has reached the slot's shopLevel (activity_table shopLevelDisplayDataDict lists the tier-5 slots at
 //     level 5 and the tier-6 slots at level 6; PRTS 帮助 "仅在调度中心等级 ≥ 干员所在等阶"). The price is the slot's (any
-//     chess of its tier: 4). Effects that grant a random operator from the shared pool never draw it.
+//     chess of its tier: 4).
+//   * random grants (diyStockEntries, 0.2.0 WE2 #9): an effect, reward or 机变 card that grants this player a random
+//     operator from the pool draws its stock too — 「自选干员放入后模拟中的补给池随机范围也将被相应扩大」 (bilibili), "调度中心
+//     随机资源的范围将被扩大" (PRTS 新手教程) — under the roll's own tier rules (the effect's tier / maxTier: no 调度中心 gate,
+//     as for a preset chess) and filters (bonds read through the player's data view).
 // Installed on PlayerState.prototype by server/match/PlayerState.js (a method container: never instantiated; `this` is
 // the player state).
 
@@ -204,6 +208,17 @@ export class PlayerDiy {
     return out.length ? out : null;
   }
 
+  /**
+   * The stock entries a random grant of this player draws besides the shared pool (see the header): every slotted piece
+   * with copies left, whatever the 调度中心 level (the roll's own tier rules apply), or null (none).
+   * @returns {Array<[string, { cap: number, left: number, tier: number, shopLevel: number }]> | null}
+   */
+  diyStockEntries() {
+    if (!this.diyStock || !this.diyStock.entries.size) return null;
+    const out = [...this.diyStock.entries].filter(([, e]) => e.left > 0);
+    return out.length ? out : null;
+  }
+
   /**
    * The 自选 pick a chess id (normal or elite) of this player fields — its slot's — or null (not a slotted slot).
    * @param {string} id