Release v0.2.3 with macOS builds and cross-platform PDF fixes

[breslee1707]

Summary

• prevent large PDF finalization hangs by emitting only the mono output and using a fast serialization path for documents >= 200 pages or >= 50 MB
• normalize reflected text matrices so translated text is not rendered upside down
• fit indented prose and dense table cells within their source bounds
• preserve Wingdings/Symbol private-use bullets on macOS and Windows
• include macOS Apple Silicon and Intel build/release workflows
• bump APP_VERSION to 0.2.3

Validation

• python -m unittest discover -s tests -v (106 passed)
• python -m pip check
• Ruff hard-error checks
• Windows PyInstaller build and packaged GUI smoke-test (exit 0)
• visual/full-page QA on 4-page and 187-page regression PDFs; 0 null glyphs, replacement glyphs, placeholders, or spans outside the page canvas

Generated PDFs, models, caches, build outputs, and AGENTS.md are not included.