The admin SPA never called POST /billing/invoices, so every session had
invoice_uuid = null and the view-invoice buttons on the patient services
tab (and MyPatients visit modal) were permanently disabled. Add a shared
useIssueInvoice hook (idempotent create + finalize when draft) and wire
it into:
- DetailsStep: the wizard's final step now really issues the invoice
- SessionServiceCard / PatientDetailPage: clicking view-invoice on a
session without an invoice issues it first, then opens the summary
- MyPatientsPage visit modal: same, replacing the dead disabled button
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>