feat(playable): 首个 Mac 联网内测版 STB-01 soak 工具与发布状态文档

- 新增 script/playable_soak.sh：先做 soak 配置/资源校验，无 --allow-gameplay
  只校验不启动客户端；N(>=10) 次独立正常退出运行 + 墙钟 soak，失败即停止后续
  运行并记 BLOCKED；写本批次 release-manifest.json 后聚合
- run_client_gate.sh：确认的故障代理对所有 suite 启动（共享场景的退出运行也经代理）；
  soak 超时下限只约束 soak 客户端（validate_soak 增加 soak_client 参数）
- 新增本地 127.0.0.1 故障代理、RSS 采样/内存判定、窗口/指标/流程模块及其测试
- forest_mob_render_test 输出 PASS/FAIL 标记，供 rendering_batch_test.sh 识别
- 新增 docs/FIRST-MAC-PLAYABLE-STATUS.md：如实记录 PASS/BLOCKED、已知问题与环境需求
- .gitignore 排除本地场景配置、凭据文件与运行输出

离线回归：rendering_batch_test.sh failures=0，playable_gate_test.sh PASS，
node 夹具测试 PASS。未联网运行，未重建候选包。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Ft3kXpNdLbKEfg5uDLfqVF

test/playable/report.valid.json

@@ -1,6 +1,6 @@
 {
   "schema_version": 1,
-  "run_id": "fixture-valid",
+  "run_id": "fixture-run",
   "suite": "playable",
   "status": "PASS",
   "build": {
@@ -9,11 +9,37 @@
     "pck_sha256": "cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc",
     "arch": "arm64"
   },
-  "environment": {"os": "macOS", "renderer": "Metal", "resolution": [1280, 720]},
-  "cases": [{"id": "FIXTURE-01", "status": "PASS", "duration_ms": 1, "reason": "ok", "evidence": []}],
+  "environment": {
+    "os": "macOS",
+    "renderer": "Metal",
+    "resolution": [
+      1280,
+      720
+    ]
+  },
+  "cases": [
+    {
+      "id": "FIXTURE-01",
+      "status": "PASS",
+      "duration_ms": 1,
+      "reason": "ok",
+      "evidence": []
+    }
+  ],
+  "required_cases": [
+    "FIXTURE-01"
+  ],
   "events": "events.jsonl",
+  "event_count": 1,
   "failures": [],
   "blocked": [],
-  "coverage": {"required": 1, "passed": 1},
-  "exit_gate": {"checked": false, "process_code": null, "errors": []}
+  "coverage": {
+    "required": 1,
+    "passed": 1
+  },
+  "exit_gate": {
+    "checked": false,
+    "process_code": null,
+    "errors": []
+  }
 }