Task: Enforce live Buy TCOIN approval gate and disabled fallback

[KazanderDad]

Parent Goal: #81
Depends on: Preview Buy TCOIN sandbox evidence and explicit human approval
Blocks: Live Buy TCOIN enablement

Objective

Enforce live Buy TCOIN approval gate and disabled fallback for Production.

Expected Surfaces

• Production Vercel env vars
• NEXT_PUBLIC_ENABLE_BUY_TCOIN_CHECKOUT
• Buy TCOIN live provider/onramp settings
• Goal Goal: Prove Preview sandbox smoke and Buy TCOIN sandbox #79 sandbox evidence
• Human approval on the main path

Scope

• Confirm sandbox evidence before considering live.
• Require explicit human approval before enabling live Buy TCOIN.
• Keep checkout disabled if live is not fully green.
• Record final decision on Goal Goal: Prove Production smoke and live Buy TCOIN gate #81.

Non-Goals

• Do not enable live Buy TCOIN automatically.
• Do not bypass main approval.

Guardrails

• Sandbox first and PR to dev; live gated behind explicit approval to main.
• If not fully green, proceed with NEXT_PUBLIC_ENABLE_BUY_TCOIN_CHECKOUT=false.

Acceptance Criteria

• Live Buy TCOIN is either explicitly approved and configured with evidence, or confirmed disabled with remaining blockers listed.
• Final go/no-go note is added to Goal Goal: Prove Production smoke and live Buy TCOIN gate #81.

Validation Plan

• Compare sandbox evidence from Goal Goal: Prove Preview sandbox smoke and Buy TCOIN sandbox #79.
• Inspect Production Buy TCOIN env/flag metadata without exposing secrets.
• Record approval link/comment if enabling live.

Stop Condition

Stop after the live Buy TCOIN decision is recorded on Goal #81.