fix(闸收敛批三): .gates/.gitignore 入库 + 脚本自愈重建

合回 master 时发现：.gates/.gitignore 未入库，receipt.json 被纳入版本管理——
它是每跑批覆写的当次回执，属中间产物。

成因：重跑闸前用 rm -rf game/tests/.gates 清目录，把 .gitignore 一起带走了；
脚本自身不重建，跑得再多次也不会回来。

- .gates/.gitignore 入库（挡 receipt.json 与 *.log）。
- run_all_gates.sh 启动时自愈：.gitignore 缺失则重建，杜绝复发。

game/tests/.gates/.gitignore

@@ -0,0 +1,4 @@
+# 本目录只入库 baseline.json（存量基线，需随代码走以保证各 worktree 判定口径一致）。
+# receipt.json 是每跑批覆写的当次回执、*.log 是跑批当场日志——两者都是中间产物，不入库。
+receipt.json
+*.log

game/tests/.gates/receipt.json

@@ -1,62 +0,0 @@
-{
- "commit": "1d4ac91e3bda95048e65b7ac17c29a8e6198b80f",
- "commit_short": "1d4ac91e",
- "timestamp": "2026-10-15T21:42:07+08:00",
- "quick_mode": false,
- "first_baseline_run": true,
- "gates": [
-  {
-   "name": "01 冒烟全量",
-   "exit": "0",
-   "fingerprint": "green"
-  },
-  {
-   "name": "02 单元套件",
-   "exit": "0",
-   "fingerprint": "green"
-  },
-  {
-   "name": "03 探针 --click",
-   "exit": "0",
-   "fingerprint": "green"
-  },
-  {
-   "name": "04 探针 --full",
-   "exit": "0",
-   "fingerprint": "green"
-  },
-  {
-   "name": "05 渲染闸",
-   "exit": "0",
-   "fingerprint": "green"
-  },
-  {
-   "name": "06 gdd_lint",
-   "exit": "0",
-   "fingerprint": "green"
-  },
-  {
-   "name": "07 doc_link",
-   "exit": "0",
-   "fingerprint": "green"
-  },
-  {
-   "name": "08 doc_term",
-   "exit": "0",
-   "fingerprint": "green"
-  },
-  {
-   "name": "09 静态扫描",
-   "exit": "1",
-   "fingerprint": "3220614b09c4"
-  },
-  {
-   "name": "10 熵增闸",
-   "exit": "0",
-   "fingerprint": "green"
-  }
- ],
- "changed_vs_baseline": [],
- "inherited_red": [],
- "all_green": true
-}