Owner-issued payment link

flowchart TD
      A["Owner opens quote console"] --> B["Clicks issue payment link"]
      B --> C["POST /owner/quote/<ref>/lien-paiement"]
      C --> D{"Staff authenticated?"}
      D -- No --> E["404"]
      D -- Yes --> F{"Target?"}
      F -- "mission" --> G["payment_for_quote"]
      F -- "expenses" --> H["payment_for_settlement"]
      G --> I["Create Payment row with reference"]
      H --> I
      I --> J["AuditEvent: payment_link_issued"]
      J --> K["Show absolute URL to owner"]
      K --> L["Owner sends URL to buyer"]
      L --> M["Buyer opens /paiement/<ref>/"]
      M --> N{"Already settled?"}
      N -- Yes --> O["Redirect to return page"]
      N -- No --> P["Show payment page + identity form"]
      P --> Q["Visitor corrects details if needed"]
      Q --> R["POST /paiement/<ref>/demarrer/"]
      R --> S["Create Stripe Checkout session"]
      S --> T["Redirect to Stripe"]
      T --> U{"Buyer action"}
      U -- "Pays" --> V["Webhook settles + grant entitlement"]
      U -- "Cancels" --> W["Nothing charged"]
      V --> X{"Subscription?"]
      X -- Yes --> Y["Show billing portal link"]
      X -- No --> Z["Show receipt + download links"]