[Smart Accounts Kit ] add delegations buyer guide for x402

[AyushBherwani1998]

Description

• Add x402 buyers guide using delegations.

Issue(s) fixed

Fixes #

Preview

Checklist

• If this PR updates or adds documentation content that changes or adds technical meaning, it has received an approval from an engineer or DevRel from the relevant team.
• If this PR updates or adds documentation content, it has received an approval from a technical writer.

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• I've created a new issue (or assigned myself to an existing issue) describing what this PR addresses.

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Note

Low Risk
Low risk: documentation-only changes plus a small correction to code snippets (delegationManager field location) that could affect readers but not runtime behavior.

Overview
Adds a new x402 section to the Smart Accounts Kit docs sidebar with Buyer guides covering paying x402-protected APIs via delegations, Advanced Permissions with fixed allowance, and recurring payments.

Updates existing Advanced Permissions/ERC-7710 reference examples to extract delegationManager directly from the permission response (permissionsResponse[0].delegationManager) instead of signerMeta.delegationManager.

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Project	Deployment	Actions	Updated (UTC)
metamask-docs	Ready	Preview, Comment	May 14, 2026 4:47am

[bgravenorst]

Some feedback

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Cursor Bugbot has reviewed your changes and found 1 potential issue.

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[alexandratran]

Minor feedback

[bgravenorst]

lgtm