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/codingplan/no_balance.txt

@@ -0,0 +1 @@
+sk-sp-a89b3b36ab144f559b9e90a5984dadfc|https://github.com/hiyenwong/migi/blob/b0d67189bdfa5b4731e1831ca209ef7eec69bfed/src/bin/migi-client-comp.rs|models=200 chat=429: {"error":{"code":"insufficient_quota","message":"month allocated quota exceeded.","param":null,"type":"invalid_request_error"},"request_id":