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

README.md

@@ -114,7 +114,7 @@ npm start                   # http://localhost:3000
 ## 测试
 
 ```bash
-node --test                 # 单元 + 集成测试（约 2750 项；缺少素材 / 浏览器的用例会自动跳过）
+node --test                 # 单元 + 集成测试（约 2840 项；缺少素材 / 浏览器的用例会自动跳过）
 SP_E2E=1 node --test test/ui/mock.e2e.test.js      # 需要本机 Chrome（CHROME_PATH 可指定路径）
 SP_REAL_E2E=1 node --test test/ui/real.e2e.test.js # 需要 Chrome + 已下载素材
 ```