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/mimo/key_01_sk-cx8s34vwo7n1j79.txt

@@ -0,0 +1,8 @@
+Provider: Xiaomi MiMo (token plan)
+Key: sk-cx8s34vwo7n1j79mm5l07228ib6x3tfkqdtzz17rxf96p0x0
+OpenAI base URL: https://api.xiaomimimo.com/v1
+Anthropic base URL: https://api.xiaomimimo.com/anthropic
+Source: https://github.com/Wjs226213/obsidian/blob/e5bf1ea61d734fcd4060e44ab4c225cc8d245f68/js-Note/.claudian/claudian-settings.json
+Auth: Bearer / x-api-key
+Models: mimo-v2.5
+Note: full key is 51 chars; sk-cx- prefix.