Evergreen farms (pos)

- Diagnosed and resolved "checkout.session.completed" 400 errors occurring after successful Stripe payments.
- Identified the root cause as the unique MongoDB "username" index rejecting multiple in-flight companies with "null" usernames ("E11000").
- Replaced the affected unique indexes with partial unique indexes that apply only to string values for "username", "dbName", and "logo".
- Added migration script "scripts/fix-company-partial-unique-indexes.js" to update existing database indexes.
- Restored successful company creation and provisioning for paid Gallery signups after Stripe payment completion.
- Redesigned the Gallery payment success UI with professional brand green and white styling.
- Added a loading spinner and activation state while the company is being provisioned.
- Improved the post-provisioning success screen with a cleaner, professional details layout.
- Removed the workspace domain from the payment success UI.
- Updated the Login URL and “Go to login” action to use the global "accounts.{domain}/login" URL.
- Added optional product application URLs such as "pos." and "superset." separately from the main login URL.
- Created a new professional welcome email template "onboardingCompanyReady.ejs".
- Updated the welcome email to use the global Accounts login URL instead of "{tenant}.localhost".
- Added payment invoice PDF attachment to the welcome email when an invoice is available.
- Updated company provisioning so newly created companies default to "Active".
- Prevented soft verification warnings from automatically changing newly provisioned companies to "InActive".
- Completed the related Gallery paid-only signup flow with password and Stripe payment integration.
- Implemented and refined payment success and payment failed routes.
- Fixed tenant and e-commerce host handling for domain and product URL generation.