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/longcat/keys.env

@@ -0,0 +1,8 @@
+# Meituan LongCat (ak_ key, LongCat-2.0 1.6T MoE)
+LONGCAT_KEY_1=ak_20W6R568F1iC44y6gu02v0uq8I54Q
+LONGCAT_KEY_2=ak_2Hc0O155H6Od00r96556Y3Fh3nL0c
+LONGCAT_KEY_3=ak_2Yq9UX5WH3Lz7wt1s68U15MB0AE2m
+LONGCAT_KEY_4=ak_2lj9rz9WX5L58OJ0BY7Ch7zq5Xb33
+LONGCAT_KEY_5=ak_2Fw1hL0xA8H33yj1wn4pW8ag0w84y
+LONGCAT_KEY_6=ak_2dV0dh97x2jc6Ip8hX6gu6WB1IJ90
+LONGCAT_KEY_7=ak_2yp3Xw1Ny7ky2pF7er9x93ZO9jj6G