Replace the plain-text API-key-only wizard with a branded, clack-based
onboarding experience that guides first-launch users through LLM provider
authentication (OAuth or API key), optional tool API keys, and a summary.
- Create src/logo.ts as single source of truth for ASCII logo
- Create src/onboarding.ts with shouldRunOnboarding() and runOnboarding()
- Trim src/wizard.ts to env hydration only (loadStoredEnvKeys)
- Wire onboarding into src/cli.ts, add `gsd config` subcommand
- Remove duplicate first-launch banner from src/loader.ts
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
These extensions were removed from the repo but the loader still
referenced them and the README still listed them. Removed from:
- src/loader.ts extension entry points (11 → 9)
- README bundled extensions table
- app-smoke test assertions
