- Remove `process_mode` from `MarkdownOptions` (it controlled the
pipeline, not markdown formatting)
- Remove dead `text` field from `PdfProcessResult`
- Add `PdfOptions` builder consolidating mode, detection, markdown,
and page filter configuration
- Add convenience functions: `detect_pdf()`, `detect_pdf_mem()`,
`process_pdf_with_options()`, `process_pdf_mem_with_options()`
- Eliminate double document parsing: load once, share between
detection and extraction via internal `pub(crate)` helpers
- Deprecate old `process_pdf_with_config*` functions (kept as shims)
- Update binaries to use new API
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
