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/siliconflow/keys.env

@@ -0,0 +1,7 @@
+# OK {"id":"019fbd7c77578aa069470a2e659ae87e","object":"chat.comp
+# src: https://github.com/Dying-Autumn/Personal-Knowledge-Base-Management-System/blob/191776aefecb14d6da0720b631abb0ff4e87998a/R2R/docker/env/r2r-full.env
+SILICONFLOW_API_KEY=sk-uqrbjystsbssskbzxqjypiszvldanfguwwfeinsapotkflll
+
+# RESTRICTED (KYC-gated, not 401 but 403 identity verification required)
+# src: https://github.com/123fjh/circuitmind/blob/HEAD/GUI/utils/config.py
+SILICONFLOW_API_KEY=sk-ptyrqcoakodsijdqglxbzucezfvdmdolzxxfafdpozixljdr