Playtest #6 follow-up (v2.5.1): leader HP review — 直接乘算, one debuff instance, 999 layer cap, 限伤; elite to the board; 假想敌：胄 kit

- co-op leaders died within seconds: leader HP is the official data (40 values pinned); bond / strategy / item /
  机变 / 特质 "+X%" bonuses now add up (PRTS 直接乘算) instead of compounding; a same-named enemy debuff keeps one
  (strongest) instance per target (奥术 across a pair field); leader parts pass damage 1:1; fixed co-op pool (the user's call)
- official limits read from the client: each bond stops at 999 layers (MAX_GARRISON_STACK); a leader hit of 300000+ in
  boss / hidden battles is cancelled (MAX_BATTLE_DAMAGE, 限伤) — shared/constants.js switches, research 11
- a merge that consumes a deployed copy puts the elite on that tile and facing (user-confirmed); gold target highlight,
  promotion effect
- 假想敌：胄 per PRTS: one shell, shells within range, any drone death costs 2 % max HP, 剑/锤 sorties and 瘫痪
- DESIGN §20.10–§20.14; 2842 unit tests, all 28 browser suites green; Chrome = Node on boss fields

server/match/finalAssault.js

@@ -8,10 +8,13 @@
 //     RIGHT side (the sim mirrors the right side: board col c → field col 20 − c with the piece direction RIGHT ↔
 //     LEFT, UP / DOWN unchanged (DESIGN §3, research 09 §1.2 ConvertChessPositionInfoToBossMap); board rows 9–12 →
 //     boss rows 2–5, sim/constants BOSS_ROW_OFFSET). `bossFieldPlacement` gives that mapping for UIs / tools.
-//   * Shared boss HP pool (research 08 §6 #7, DESIGN §14 corrections): co-op = bloodPoint[difficulty] as is — split
-//     leaders share it, "敌方领袖的总生命值不变", no alive-player factor; solo = bloodPoint × config bossHpScale.solo (0.25,
-//     flagged unknown); × the tuning bossHpMul when data/tuning.json still has one (docs/BALANCE.md); shared by every
-//     boss field; bosses are never scaled by enemyScale.
+//   * Shared boss HP pool (DESIGN §20.10, GameData.bossPoolShare): one pool shared by every boss field (official tip
+//     "所有人将一起对敌方领袖造成伤害"); co-op = bloodPoint[difficulty] whatever the number of alive players (notice 5114's
+//     "敌方领袖的总生命值不变" is about the mirrored copies of a pair field sharing it, not about that number); config
+//     bossHpScale.aliveScaling true scales it × alive / 4 (巴哈姆特 12294 "聯機隊友(撤退/死掉)變少，最後boss血條也會變少" — one
+//     community note, no proportion; off until the user confirms it); solo = bloodPoint × config bossHpScale.solo (0.25,
+//     flagged unknown); × the tuning bossHpMul when data/tuning.json still has one (docs/BALANCE.md); bosses are never
+//     scaled by enemyScale.
 //   * Overtime: bossTurnHpReduceTime counts REAL seconds like the level's 120 s maxPlayTime (which runs out first; the
 //     battle goes on): from 150 real s (300 game s on the 2× field clock) the team loses bossOvertimeDrainPerSec (1) LP
 //     per real second (gamedata.js bossOvertimeDue); m.public.deadline = the 120 s countdown, m.public.overtimeAt = the
@@ -51,22 +54,22 @@ export function pairPlayers(alive) {
   return groups;
 }
 
-/** Shared boss HP for a boss id. */
+/** Shared boss HP for a boss id with `aliveCount` alive players (GameData.bossPoolShare; omitted ⇒ a full team). */
 export function bossPoolHp(gd, bossId, aliveCount) {
   const boss = gd.boss(bossId);
   const diff = gd.difficulty;
   let base = boss && boss.bloodPoint && Number.isFinite(boss.bloodPoint[diff]) ? boss.bloodPoint[diff] : null;
   if (base == null && boss && boss.bloodPoint) base = Object.values(boss.bloodPoint).find((v) => Number.isFinite(v)) ?? null;
   if (base == null) base = 500000;
-  const scale = gd.mode.bossHpScale && typeof gd.mode.bossHpScale === 'object' ? gd.mode.bossHpScale : {};
-  const cfg = gd.config.bossHpScale && typeof gd.config.bossHpScale === 'object' ? gd.config.bossHpScale : {};
   const tune = typeof gd.bossHpMul === 'function' ? gd.bossHpMul(bossId) : 1;
-  if (gd.isSolo) {
-    const s = Number.isFinite(scale.solo) ? scale.solo : Number.isFinite(cfg.solo) ? cfg.solo : 0.25;
-    return Math.max(1, Math.round(base * s * tune));
+  let share;
+  if (typeof gd.bossPoolShare === 'function') share = gd.bossPoolShare(aliveCount);
+  else {
+    const scale = gd.mode.bossHpScale && typeof gd.mode.bossHpScale === 'object' ? gd.mode.bossHpScale : {};
+    const cfg = gd.config.bossHpScale && typeof gd.config.bossHpScale === 'object' ? gd.config.bossHpScale : {};
+    share = gd.isSolo ? (Number.isFinite(scale.solo) ? scale.solo : Number.isFinite(cfg.solo) ? cfg.solo : 0.25) : 1;
   }
-  void aliveCount; // co-op: the same pool whatever the number of alive players
-  return Math.max(1, Math.round(base * tune));
+  return Math.max(1, Math.round(base * share * tune));
 }
 
 /**