AR connector docs

[matteobusnelli-mews]

Summary

Adds public Connector API documentation for the new accountsReceivable/getStatus operation introduced in the monolith by MewsSystems/mews#82853 (FINTECH-18747).

This documentation work is tracked as FINTECH-18749.

Changes:

• New operation page connector-api/operations/accountsreceivable.md (generated via _generator).
• _generator/types.yaml updated with cross-page references for AccountsReceivableGetStatusParameters, AccountsReceivableGetStatusResponse, and AccountsReceivableStatusEnum.
• SUMMARY.md updated to list the new "Accounts Receivable" page under Operations.
• changelog/README.md entry for 2026-06-01, including the cross-field business rule: an enterprise must be treated as Accounts Receivable enabled only when the response is exactly { "Status": "Active", "IsWireTransferEnabled": true }; in any other combination the legacy posting flow must be used.

The operation is marked beta in the changelog — the endpoint is being rolled out ahead of the July 2026 Accounts Receivable general availability and is currently exposed only to selected partners (Omniboost).

Checklist

• Documentation follows the contribution guidelines
• Changelog accurately describes all changes
• All hyperlinks tested
• SUMMARY.md updated if new pages added

API

• Changelog highlights the affected endpoints or operations
• Changelog highlights any deprecations — N/A, no deprecations introduced
• Deprecation Table updated if any deprecations — N/A, no deprecations introduced