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

test/e2e/fastServer.mjs

@@ -10,6 +10,8 @@
 // SP_IDLE_BOTS=1: AI seats only ready up (no shop, no board) — test/ui/playtest2.real.e2e.test.js observes their battles.
 // SP_START_ITEMS=<itemId,…>: the starter kit also puts these items into the hand (test/ui/leftovers.e2e.test.js: three
 // distinct equipment items → the equip-replace dialog).
+// SP_START_SHOP=<chessId,…>: the starter kit also stocks the first shop slots with these chess at their normal price
+// (test/ui/playtest6-elite.e2e.test.js: the copy that completes a merge).
 // Not a test file (node --test runs it as a no-op module when NODE_TEST_CONTEXT is set).
 
 import { startServer } from '../../server/index.js';
@@ -25,6 +27,7 @@ if (!process.env.NODE_TEST_CONTEXT) {
   const idleBots = process.env.SP_IDLE_BOTS === '1';
   const kitIds = String(process.env.SP_START_CHESS || '').split(',').map((x) => x.trim()).filter(Boolean);
   const kitItems = String(process.env.SP_START_ITEMS || '').split(',').map((x) => x.trim()).filter(Boolean);
+  const kitShop = String(process.env.SP_START_SHOP || '').split(',').map((x) => x.trim()).filter(Boolean);
 
   class FastMatch extends Match {
     constructor(opts) {
@@ -75,6 +78,9 @@ if (!process.env.NODE_TEST_CONTEXT) {
         if (slot < 0 || !this.gd.item(itemId)) continue;
         try { ps.hand[slot] = ps.newPiece('item', itemId); } catch { /* best effort */ }
       }
+      kitShop.forEach((id, i) => {
+        if (i < ps.shop.slots.length && this.gd.chess(id)) ps.shop.slots[i] = { kind: 'chess', id, basePrice: this.gd.chessPrice(id), frozen: false, sold: false };
+      });
       ps.addFunds(20, { reason: 'income' });
       ps.recompute();
     }