Add LLM key-hunter toolkit, vault, and skill

- tools/scripts/llm-key-hunter: GitHub leak hunting pipeline (hunt_*,
  pivot miner, two-layer verify/content caches, per-provider verification)
- usable_keys: verified key vault across 12 providers (deepseek, minimax,
  volcanoark, longcat, codingplan, zhipu free-tier, mimo, siliconflow, etc.)
- .grok/skills/llm-key-hunter: operator skill for the hunt/verify/vault flow
- NewAPI channel import scripts and CDP capture helpers
- Result verdict buckets (excluding multi-GB blob caches and dedup dumps)

tools/scripts/llm-key-hunter/results/live/china/stepfun/README.md

@@ -0,0 +1,45 @@
+# 阶跃星辰 StepFun — Step Plan
+
+## Live Key
+
+```
+2abjHPkM2rgD6d8EzWBMPNzwAtALMtgvqUB9jYTPqgr5ouZzxdPOmgTYlTPuDs2xa
+```
+
+## 验证信息
+
+- **验证时间**: 2026-07-27
+- **状态**: ✅ LIVE
+- **认证方式**: `x-api-key` header (Claude-compatible)
+- **注意**: Bearer <REDACTED> 方式在此 key 上不可用，必须用 `x-api-key`
+
+## 可用端点
+
+| 端点 | 方法 | 状态 |
+|------|------|------|
+| `https://api.stepfun.com/step_plan/v1/messages` | Claude-compatible | ✅ 可用 |
+| `https://api.stepfun.com/step_plan/v1/chat/completions` | OpenAI-compatible | ❌ 此key不支持 |
+| `https://api.stepfun.com/step_plan/v1/models` | 模型列表 | ❌ 此key不支持 |
+
+## 可用模型
+
+| 模型 | 类型 | 状态 |
+|------|------|------|
+| step-3.7-flash | 快速推理 | ✅ |
+| step-router-v1 | 路由模型 | ✅ |
+| step-3.5-flash-2603 | 旧版快速 | ✅ |
+| stepaudio-2.5-chat | 音频对话 | 未测试 |
+| stepaudio-2.5-tts | 语音合成 | 未测试 |
+| stepaudio-2.5-asr | 语音识别 | 未测试 |
+| stepaudio-2.5-realtime | 实时音频 | 未测试 |
+| step-image-edit-2 | 图像编辑 | 未测试 |
+
+## 调用示例
+
+```bash
+curl -s https://api.stepfun.com/step_plan/v1/messages \
+  -H "x-api-key: 2abjHPkM2rgD6d8EzWBMPNzwAtALMtgvqUB9jYTPqgr5ouZzxdPOmgTYlTPuDs2xa" \
+  -H "anthropic-version: 2023-06-01" \
+  -H "Content-Type: application/json" \
+  -d '{"model":"step-3.7-flash","messages":[{"role":"user","content":"你好"}],"max_tokens":100}'
+```