docs: clarify Selfie Check integration

[Takaros999]

This PR clarifies Selfie Check integration after developer feedback:

• clarifies that World App is the only prerequisite; no Orb or passport credential is required
• explains that selfieCheckLegacy is World ID 3.0-only and World ID 4.0 Selfie Check is not yet available
• standardizes docs and OpenAPI on selfie, with face documented only as a compatibility alias
• distinguishes host callback failures from camera or credential failures

[mintlify]

Preview deployment for your docs. Learn more about Mintlify Previews.

Project	Status	Preview	Updated (UTC)
world	🟢 Ready	View Preview	Jul 28, 2026, 5:37 AM

💡 Tip: Enable Workflows to automatically generate PRs for you.

[chatgpt-codex-connector]

💡 Codex Review

Here are some automated review suggestions for this pull request.

Reviewed commit: 3fdcde27e0

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

Include the documented face alias in the enum

The description says that legacy requests using verification_level: "face" remain accepted, but the new OpenAPI enum excludes that value. Any generated client or request validator that enforces this schema will reject those backward-compatible requests before they reach /api/v2/verify/{app_id}. Add face to the enum, marking it deprecated in the description if appropriate.

Useful? React with 👍 / 👎.

[mintlify]

Preview deployment for your docs. Learn more about Mintlify Previews.

Project	Status	Preview	Updated (UTC)
world	🟡 Building	–	Jul 28, 2026, 5:36 AM

💡 Tip: Enable Workflows to automatically generate PRs for you.