What problem does it solve? Schools using the Toollab platform need legally compliant tuition invoices for families, including correct French VAT regime mentions (CGI articles), deterministic invoice numbering, and paid/unpaid status display, without adding any Composer PDF dependency. ## Core Features & Use Cases - Invoice endpoint: GET /api/families/{family}/paiements/facture returns a downloadable PDF reflecting the current payment state, accessible to both staff and family members via callerCanAccessFamily. - Hand-written PDF 1.4 service: FacturePdfService builds a six-object A4 PDF with exact xref offsets, WinAnsi-encoded Helvetica text, and width-table-based right/center alignment, with zero external dependencies. - VAT regime handling: Prints the correct CGI mention (261 7-1°, 261 4-4°, 293 B) or an HT/TVA 20%/TTC breakdown for assujetti schools, driven by schools.vat_mode. - Use Case: A parent opens the family payment page, clicks the Facture PDF button, and downloads an invoice showing total, amount paid, exemptions, and remaining balance with the correct fiscal footer. ## Quick Start Ask the AI to modify the invoice layout or VAT mentions in FacturePdfService, then regenerate and visually open the PDF via the curl command in the skill to verify the xref offsets and alignment.