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/deepseek/keys.env

@@ -0,0 +1,5 @@
+# DeepSeek live keys (balance rechecked)
+DEEPSEEK_API_KEY_01=sk-a29e901493ee46e290f20696adbfa4a3  # balance=94.42
+DEEPSEEK_API_KEY_02=sk-f472f8cf87654d27aae3613f2b5c3a19  # balance=1.45
+DEEPSEEK_API_KEY_03=sk-283b965c14624d50992f4d602ffe6bd9  # balance=-0.08
+DEEPSEEK_API_KEY_04=sk-6f66664876aa4e6c9fdf81deb35b9eca  # balance=0.26