docs: integrate Commerce Payments Protocol into payment guides

[youssefea]

What changed? Why?

Integrates Commerce Payments Protocol v1.1.0 into the established Accept Payments solution without changing its information architecture or guide format.

• Preserves the existing Take a Payment, Confirm and Reconcile, Return and Pay Out, and Accept Agentic Payments groups.
• Preserves every existing payment route and leaves the payout, split, and x402 guides in place.
• Reworks request, authorize, capture, partial capture, void/reclaim, scheduled charge, refund, verify, watch, and reconcile around Commerce Payments Protocol.
• Keeps the existing page pattern: interactive mock demo, implementation guidance, verified code snippet, checks, warnings, and related-guide cards.
• Updates the PaymentsDemo flows to model PaymentInfo, collector approval, escrowed authorization, capture, protocol refund accounting, event verification, and reconciliation.
• Adds synchronized, typechecked viem fixtures and a shared v1.1.0 escrow ABI/address module for the published snippets.

Notes to reviewers

The navigation and Base Std routing are byte-for-byte unchanged from master. The protocol content is based on base/commerce-payments main at commit b748fdd7 from September 3, 2026.

The docs call out the important implementation details without turning the Build on Base section into protocol reference docs: successful onchain authorization is the funds guarantee, captures use absolute fee amounts, void and payer reclaim return capturable funds, and refunds require new liquidity from a refund collector.

How has it been tested?

• Targeted MDX lint for the complete Accept Payments directory and navigation titles
• node scripts/verify-doc-samples.js — 69 synchronized samples
• TypeScript sample typecheck
• node scripts/validate-docs-structure.js
• npm test — 85 passing
• PaymentsDemo JSX compiled with esbuild
• Every existing payment route and the Get Started page returns HTTP 200 locally
• Final PR diff is whitespace-clean

Screenshots

Use the Mintlify preview below or the local preview at http://localhost:3000/get-started/accept-payments.

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Project	Status	Preview	Updated
base	🟢 Ready	View Preview	Sep 16, 2026, 8:50 PM

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[cb-heimdall]

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