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/zhipu_glm52_live/summary.json

@@ -0,0 +1,7 @@
+{
+  "USABLE": 0,
+  "NO_BALANCE": 207,
+  "NO_ACCESS": 1,
+  "DEAD": 101,
+  "UNKNOWN": 0
+}