fix(importers): preserve quoted CSV headers

[Bortlesboat]

Summary

Semicolon- and tab-delimited statements with commas in quoted headers now retain their columns for mapping and import. Detection respects the first CSV record when quoted headers span lines or records use CR-only endings.

Validation

• Eight regression cases cover quoted punctuation, escaped quotes, multiline headers, line endings and a mapped import. Six fail before the fix; all pass afterward.
• All 540 tests, formatting, typecheck, dependency license check and package builds pass.
• Browser upload/mapping and API previews preserve both synthetic executions, with correct quantities/prices and zero skipped rows.
• Production compilation, type validation and all 46 static pages complete on Windows. Final standalone packaging fails with symlink EPERM; the normal production server starts and serves the verified preview.

Post-Deploy Monitoring & Validation

Preview a semicolon- or tab-delimited export with commas in quoted headers. Confirm its columns, execution count, quantities and prices match the source before committing the import.