test: commerce and entitlement e2e test plan

[daopunk]

Parent: #68

Summary

Manual + automated test checklist before enabling ENTITLEMENTS__ENFORCE=true in prod.

Scenarios

• Stripe test checkout → !link → individual feature works
• Group checkout → link → claim → !translate-all-on
• Alpha code → full bundle for 90 days → expiry blocks features
• Alpha user still works after paid gating code merges (regression)
• past_due / cancel via Stripe test clocks
• Unlinked user invited bot → helpful denial, no NEAR spend
• Local dev with enforce=false unchanged

Deliverables

• Checklist in docs/ or issue comment
• Stripe test mode fixtures documented

[daopunk]

Parent epic retargeted: #13 → #68.