1.8.1

New

• /doudizhu rule airplane <3|6> and /doudizhu rule ai <0|1|2> — the options screen only carries switches, so the exact values are set from chat. Both are available to regular players (no cheats needed).
• AI deep search — the built-in AI can switch to the offline-validated PIMC search policy (sampling + perfect-information minimax, with a node budget and a legality fallback). It is orthogonal to "AI cautious", so "cautious style + deep search" is a valid combination.
• Farmer cooperation (CooperativePolicy) — an AI farmer no longer beats its own teammate (unless it can go out in one move), and it always blocks with its cheapest play when the landlord is down to 2 cards or fewer. Six offline assertions in CoopHarnessMain, wired into logic-check.

Fixed

• No more sliders on the options screen — "airplane cap" and "AI level" used to be sliders, and Charta draws the slider handle outside the slot (reported with a screenshot). Both are checkboxes now.
• Option hints with a bracketed range (e.g. （2~6）) no longer get cut mid-line; they break explicitly.
• After moving the strong search policy into the engine, game/engine/ is still free of Minecraft imports (logic-check verifies that on every run).

中文

新增

• /doudizhu rule airplane <3|6> 与 /doudizhu rule ai <0|1|2>：选项界面只有开关，精确数值在聊天栏设置（普通玩家即可用，不需要作弊）。
• AI 强化搜索：内置 AI 可以改用离线验证过的 PIMC 搜索策略（采样 + 完全信息极小极大，带节点预算与兜底校验）；与「AI 保守」正交，可组合成"保守风格 + 强搜索"。
• 农民配合（CooperativePolicy）：上一手是队友打的就不压（除非能一把走完）；地主只剩 ≤ 2 张时必定挑一手最便宜的牌封杀。离线断言 CoopHarnessMain 6 条，挂在 logic-check 里。

修复

• 选项界面不再有滑块：飞机带牌上限与 AI 难度原本是滑块，Charta 的滑块手柄会被画到槽位外面（玩家截图反馈）；两者都改成复选框。
• 选项提示里带括号的范围（如 （2~6））改成显式换行，不再被自动折行切断。
• 把强搜索策略搬进引擎后，game/engine/ 仍然零 Minecraft 依赖（logic-check 每次都会校验）。