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/usable_keys/codingplan/key_05_sk-sp-febb8ce375bd.txt

@@ -0,0 +1,7 @@
+Provider: Alibaba Bailian Coding Plan
+Key: sk-sp-febb8ce375bd4eb7ad44db55d3b8fb0c
+Base URL: https://coding.dashscope.aliyuncs.com/v1
+Source: https://github.com/zlj0402/LeetCode/blob/3244b597b0a80cf149bd4e60df8f61aa1d39ae7c/litellm_config.yaml
+Auth: Bearer
+Models: qwen3-coder-plus, qwen3-coder-next, qwen3-max-2026-01-23, qwen3.5-plus, qwen3.6-plus, qwen3.7-plus, glm-4.7, glm-5, kimi-k2.5, MiniMax-M2.5
+Detail: models=200 chat 200 {"created":1785593858,"usage":{"completion_tokens":5,"prompt_tokens":9,"prompt_tokens_details":{"cac