Add get_statement_data (open invoices, aging buckets, totals, formatted
customer + company addresses) and generate_statements, which renders one
page per customer via a Jinja template and returns a printable HTML
document. Recipient window geometry (top:1.9in/left:1.125in) mirrors the
existing double-window print formats for #10 envelope compatibility; each
page uses page-break-after:always. Late fee is a zero placeholder here.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Add ns_app/api/statements.py with get_customers_with_overdue_invoices
(one aggregated row per customer with overdue Sales Invoices) plus the
_get_outstanding_invoices / _aging_bucket helpers used to build the
per-customer statement.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
