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/deepseek/usable.txt

@@ -0,0 +1 @@
+sk-283b965c14624d50992f4d602ffe6bd9|https://github.com/qidu/model_proxy_v3/blob/84aeed1ff3dd48806f7514b5cbc08d54e107cc1e/testcases/06_integration/integration.test.js