云卷入囊，六境同携 · Bundle PDF support in npm

[eric8810]

Summary

• expose PDF and multi-page OCR directly from @arcships/light-ocr and route light-ocr report.pdf to it
• bundle the pinned PDFium addon and shared library inside each platform npm package
• keep the stable closure script-free and verify real PDF OCR without network access
• retain @arcships/light-ocr-document@0.1.1 only as a compatibility entry
• prepare the conservative 0.5.5 release and update README, roadmap, decisions, and Agent Skill

Local verification

• npm test
• npm run typecheck
• node --test bindings/node/test/cli.test.cjs
• python3 -m unittest tests.python.test_npm_release tests.python.test_npm_webgpu_release
• node tools/npm/document-smoke.cjs (HELLO 123)
• standalone bundled pdfium-loader.cjs render smoke
• python3 tools/npm_release.py ensure-unpublished --version 0.5.5