BizCore v5.1 - Mundo Marketplace Foundation (SAFE)

1) Upload/extract this ZIP into the ceylongemx.online root and overwrite files.
2) Open update-5.0.php first and click Install / Repair if Permissions says Needs repair.
3) Then open update-5.1.php and click Install Mundo v5.1.
4) Open Mundo Ecommerce from the sidebar.

v5.1 adds:
- corrected access_permissions schema (module_code)
- marketplace vendor profiles based on existing BizCore contacts
- payment gateway registry with encrypted secret storage
- courier company/API registry with encrypted credentials
- shipping-rules database foundation
- temporary/final storefront URL setting
- marketplace mode toggle

Safety:
- no existing BizCore table is dropped
- no old sales, stock, production, finance, contacts or users are deleted/reset
- installer is repeat-safe for existing tables/columns/permissions
- external payment/courier API adapters are NOT yet activated automatically; credentials can be staged safely for the next integration step
