Backend - Add automated invoice generation on completed orders

[NamFra]

Feature Request

Is your feature request related to a problem or unsupported use case? Please describe.

Currently, only partner universities are legally allowed to issue invoices, and they can do so only after we transfer the collected funds once per year.
This delay generates support tickets and dissatisfaction from learners and organizations.

A solution has now been validated with our accounting department: we are allowed to generate invoices on behalf of universities for training products and certificates, under a mandate agreement (convention de mandat).

We already have all required data available in Joanie.

Describe the solution you'd like

We need to implement automated invoice generation for each completed order (paid in full, balance = 0).

Depending on implementation complexity, several options are possible:

• Prefered option : integrate invoice download in the learner dashboard on Richie (a dedicated issue can be created after discussion).
• Fallback option: send an email generated by Joanie with a link to the invoice, while keeping it available in the Joanie BO interface.

This may result in a two-phase implementation:

• 1. Backend support in Joanie
  • Invoice model
  • Numbering sequences per organization
  • PDF generation and storage
  • Trigger on completed order
  • Email dispatch (if needed)
• 2. Frontend display in Richie
  • Add an "Invoices" section into the learner dashboard
  • Allow invoice download

The invoice must include:

• FUN header (issuer)
• Mandatory mention that FUN issues the invoice on behalf of the relevant university (mandate agreement)
• University identification details:
  • Name
  • SIRET number
  • Registered address and other contractual contact details
• Billing address (customer)
• Amount to be paid, amount paid, resulting balance = 0
• Product name
• Session dates
• ⚠️ Invoice number constraints:
  • Strictly sequential numbering per university
  • No gaps allowed (e.g., no missing “002” between 001 and 003)
  • Independent invoice sequences per organization
  • Must be different from the order number

Discovery, Documentation, Adoption, Migration Strategy

• A draft invoice template is available (attachment to this card)
  • It still requires validation from partner universities and may evolve a bit
• PayZen currently provides a simplified receipt, but legally valid invoices must be generated by Joanie
• Applies only to payments collected via credit card through our platform (not BDC or wire transfers)
• Manual invoices may still be generated temporarily, but at initial rollout, invoice numbering can start at 001 for each institution
  💪 🙏