fix: Checkout action dereferenced an absent cart session

[remedy-local-mateus]

Closes #9

Root cause

Checkout action dereferenced an absent cart session

Patch

Branch: remediation/eb6384f1-aac7-4b83-924c-05a9293b9029
Commit: 2c86a7ca229b2bdcde46f0c444347dc18d2770f7

• src/cart/checkout.ts (+8/-2)
• tests/cart/checkout.test.ts (+24/-0)

Risks

• Review the changed paths and regression coverage before merging.
• This pull request is draft and must be merged by a human.

Tests

• ✅ patched-preview: Patched preview no longer reproduces the incident

Evidence

• log — command failure reproduced
• patch — Guard cart session and add regression test
• log — command fix verified

Policy exceptions

• None — patch stayed within policy limits

Context

• Sentry: SENTRY-2051 (demo — not a real Sentry issue)
• Release: javascript-nextjs@demo
• Baseline SHA: f087aa30
• Execution: http://localhost:3000/runs/eb6384f1-aac7-4b83-924c-05a9293b9029
• Cost: $0.42

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Project	Deployment	Actions	Updated (UTC)
code-wise	Error		Jul 17, 2026 2:14pm