Extract the general Report Generator's branded cover (cover image/band,
logo, title, prepared-for/by) into shared src/lib/reportCover.ts. Financial
reports now open with the same cover: platform AccountingReportsPage via new
renderReportPdfWithCover(), and the Zoho/Board financial reports
(zohoFinancialReportPdf generators). ReportGeneratorPage refactored to use
the shared module (removes duplicated cover code).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>