feat(cli): discover gateway models dynamically

[danielsuit]

Summary

• make subc models read the selected gateway public /v1/models endpoint anonymously
• inject the live model IDs into Codex, OpenCode, Cursor, Copilot, and Pi catalogs and Claude model-picker slots
• derive discovery URLs safely from gateway origins or OpenAI API URLs
• remove stale model lists from generated profile comments and CLI documentation
• retain the bundled registry only as an explicit, warned offline fallback

Behavior

• discovery is bounded by a five-second timeout and validates the OpenAI model-list response
• no API key is sent to the public catalog
• profile-selected models remain first in generated catalogs
• newly routed models appear in CLI integrations without publishing another CLI release

Verification

• full CLI suite on supported Node 20: 20 passed
• live local subc models call against the seeded gateway at 127.0.0.1:31080
• JavaScript syntax checks
• git diff --check

Related

• platform catalog and billing mapping: subconscious-monorepo#563
• public gateway model discovery: api-gateway#469