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/source_files/cad8435f0472.txt

@@ -0,0 +1,4 @@
+ZHIPUAI_API_KEY = 'f4e8fa12b9143d8337c80a6db8bbc440.3Gs8fMATdRD6Vz0u'
+TAVILY_API_KEY = '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'
+LANGCHAIN_TRACING_V2="true"
+LANGCHAIN_API_KEY="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"