Quality practices

Reproduce defects before fixing when practical. Test normal, boundary, and failure behavior proportional to risk. Run focused checks first, then repository validation, type checking, tests, and production build. Frontend work also verifies keyboard flow, visible focus, semantics, contrast, responsive states, and error recovery.

Never expose credential values. PayPal credentials remain server-only, runtime-injected, and Sandbox-scoped. Product records and AliExpress prices or images remain tied to reviewed evidence. A green local command is not remote CI evidence; a merged commit is not deployment evidence.