feat(workpaper): the audit workpaper as a deterministic PDF (P8)

One page set a CPA can read: what was checked, through which day and state
of the books, every finding with its code and severity. No clock and no
random id, so the same findings give the same bytes.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HS8WZziDnyxunC23MUxrLp

crates/ledger-import/src/lib.rs

@@ -25,6 +25,7 @@ pub mod labels;
 pub mod pdf;
 pub mod report;
 pub mod templates;
+pub mod workpaper;
 pub mod xlsx;
 
 pub use asset_register::{asset_register_pdf, asset_register_xlsx};
@@ -43,4 +44,5 @@ pub use labels::{AssetLabel, LabelSheet, asset_labels_pdf};
 pub use pdf::{PdfError, statement_pdf};
 pub use report::{Member, ReportMeta, Row, RowKind, Statement, YearEarnings, format_amount};
 pub use templates::{ChartTemplate, EntityType, chart_template};
+pub use workpaper::{Workpaper, WorkpaperCheck, WorkpaperFinding, workpaper_pdf};
 pub use xlsx::{XlsxReport, report_to_xlsx};