docs(kyb): add file type and rejection info to document upload step

[claude]

Summary

• Adds file type requirements (application/pdf, image/jpeg, image/png) and 10 MB size limit to KYB document upload step
• Documents 422 DOCUMENT_REJECTED error for unreadable documents
• Aligns with existing KYC individual document upload guidance for consistency

This change syncs the KYB documentation with the recent OpenAPI changes in #861 that defined supported file types and document rejection responses.

Test plan

• Verified make build passes
• Verified make lint passes with 0 errors

🤖 Generated with Claude Code

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[greptile-apps]

Greptile Summary

This PR expands the KYB supporting-document upload guidance with the accepted MIME types, 10 MB size limit, and the 422 DOCUMENT_REJECTED response for unreadable documents.

• Documents supported PDF, JPEG, and PNG uploads.
• States the maximum file size.
• Describes common document-quality rejection conditions.

Confidence Score: 4/5

The PR appears safe to merge after addressing a non-blocking active-voice documentation issue.

The documented MIME types, size limit, and rejection response align with the current document-upload contract; only the passive construction in the new guidance needs cleanup.

Files Needing Attention: mintlify/snippets/kyc/kyc-unregulated.mdx

Important Files Changed

Filename	Overview
mintlify/snippets/kyc/kyc-unregulated.mdx	The new constraints and rejection behavior agree with the API contract, but one added sentence violates the documentation guide’s active-voice convention.

Prompt To Fix All With AI

### Issue 1
mintlify/snippets/kyc/kyc-unregulated.mdx:345
**Use active voice**

The passive phrase “is rejected” obscures the actor in this new guidance; naming the API directly makes the behavior clearer and follows the Mintlify documentation convention.

```suggestion
  Upload business documents (registration, articles of incorporation) and any documents required for individual beneficial owners with `POST /documents`. Reference the company by `customerId` and each owner by `beneficialOwnerId`. Files must be `application/pdf`, `image/jpeg`, or `image/png`, and 10 MB or smaller. The API rejects a scan or photo that can't be read — out of focus, cut off, or black-and-white — with `422 DOCUMENT_REJECTED`.
```

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

_{Reviews (1): Last reviewed commit: "docs(kyb): add file type and rejection i..." | Re-trigger Greptile}

[greptile-apps]

Use active voice

The passive phrase “is rejected” obscures the actor in this new guidance; naming the API directly makes the behavior clearer and follows the Mintlify documentation convention.

Suggested change

Upload business documents (registration, articles of incorporation) and any documents required for individual beneficial owners with `POST /documents`. Reference the company by `customerId` and each owner by `beneficialOwnerId`. Files must be `application/pdf`, `image/jpeg`, or `image/png`, and 10 MB or smaller. A scan or photo that can't be read — out of focus, cut off, or black-and-white — is rejected with `422 DOCUMENT_REJECTED`.

Upload business documents (registration, articles of incorporation) and any documents required for individual beneficial owners with `POST /documents`. Reference the company by `customerId` and each owner by `beneficialOwnerId`. Files must be `application/pdf`, `image/jpeg`, or `image/png`, and 10 MB or smaller. The API rejects a scan or photo that can't be read — out of focus, cut off, or black-and-white — with `422 DOCUMENT_REJECTED`.

Context Used: mintlify/AGENTS.md (source)

Prompt To Fix With AI

This is a comment left during a code review.
Path: mintlify/snippets/kyc/kyc-unregulated.mdx
Line: 345

Comment:
**Use active voice**

The passive phrase “is rejected” obscures the actor in this new guidance; naming the API directly makes the behavior clearer and follows the Mintlify documentation convention.

```suggestion
  Upload business documents (registration, articles of incorporation) and any documents required for individual beneficial owners with `POST /documents`. Reference the company by `customerId` and each owner by `beneficialOwnerId`. Files must be `application/pdf`, `image/jpeg`, or `image/png`, and 10 MB or smaller. The API rejects a scan or photo that can't be read — out of focus, cut off, or black-and-white — with `422 DOCUMENT_REJECTED`.
```

**Context Used:** mintlify/AGENTS.md ([source](https://github.com/lightsparkdev/grid-api/blob/main/mintlify/AGENTS.md))

---

For each issue above, determine whether it is valid and should be fixed. If so, fix it directly.

Note: If this suggestion doesn't match your team's coding style, reply to this and let me know. I'll remember it for next time!