Introduces `near-agent setup` command that guides users through:
- NEAR AI authentication (reuses existing OAuth flow)
- Model selection (fetches from API or shows defaults)
- Channel configuration (HTTP webhook, Telegram)
Features:
- First-run detection: auto-runs wizard if no session exists
- Respects existing settings: shows current model with keep/change option
- Saves channel secrets to ~/.near-agent/secrets/ with 0600 permissions
- Validates Telegram bot tokens via API before saving
Also fixes default NEARAI_BASE_URL to use cloud-api.near.ai (api.near.ai
returns 410 Gone).
Co-Authored-By: Claude Opus 4.5 <[email protected]>
