DocVortex 0.5.2

Changes

• Add the PDF native kernel (PR #15): reusable page snapshots, render sessions and metadata caching; a new docvortex-pdfium Rust crate for fonts, objects, paths, text colors and classification; and Rust implementations for character-to-span assignment, plain span text composition, visual run finalization, canonical line metrics, document geometry risk and style calibration, table candidate grid expansion/merging, owned bitmap crops and inline style detection. PDFium bitmap buffers transfer without worker-side PIL copies, and render mappings release independently of cyclic garbage collection.
• Switch the default compute backend to auto (preferring a compatible Rust extension, falling back to Python) and the default rendering mode to session; explicit rust still requires a compatible extension, and python/legacy remain available for fallback. Private native protocol is now 22.
• Add MinerU cold/Flash/shared benchmark harnesses, a model tape, and render-memory tooling; extensive parity tests for the text pipeline, snapshots, render sessions, font runtime and table candidates.

Compatibility

• Restart existing processes after upgrading: the private protocol changed to 22, so cached backends from older extensions are rejected and re-selected. Pure Python behavior is unchanged when no extension is present.

Full Changelog: v0.5.1...v0.5.2