Add manual help text for cq command families

[jacobcxdev]

Summary

• Add explicit help text for refresh, agent, proxy, and models command paths.
• Expand root README usage docs with command-family examples and a quick help map.
• Update CLI parsing so --help, -h, and help work across nested command paths without triggering side effects.

Testing

• Added unit coverage for root help output and manual help text by command path.
• Added regression coverage to ensure help requests do not run model refresh logic.
• Updated proxy pin coverage to verify --help leaves state unchanged.