Add launch audit handoff checklist tip

[Dusangrm]

Summary\n- Add a testing/debugging best practice for auditing AI-built apps before launch or handoff\n- Mirror the tip in the main README and the testing guide\n- Include a practical production readiness checklist example for auth, data access, secrets, APIs, payments, error states, and cleanup priorities\n\n## Why\nVibe-coded apps can work quickly but still need a small launch-readiness review before deployment or human/AI-agent handoff. This keeps the guide focused on controlled AI-assisted coding rather than only fast iteration.

[egoriklok]

Free public readiness snapshot for Add launch audit handoff checklist tip:

• Public signal: Public GitHub candidate Add launch audit handoff checklist tip #26: Add launch audit handoff checklist tip. Matched R1 terms: api, auth, control, payment, readiness.
• R1 fit: api, auth, control, payment, readiness.
• Buyer-agent check I would add before autonomous spend: explicit price/cap unit, policy/version hash, receipt or charge-evidence reference, revocation/dispute path, and allow/caution/block preflight result.
• This separates "interesting paid surface" from "safe for an agent wallet to use".

No invoice, no payment link, no delivery link, no private endpoint; this is only a free public snapshot.