Fix PDF OCR CI diagnostics and Pages actions

[Tom-R-Main]

Summary

• print and preserve the adaptive OCR quality report so runner-specific failures are actionable
• record Tesseract and Poppler versions in CI
• refresh GitHub-maintained checkout, artifact, and Pages actions

Local verification

• zig fmt --check (all tracked Zig files)
• zig build test --summary all (2,131/2,131)
• zig build --summary all
• Python benchmark hygiene suite (45 tests)
• adaptive OCR form-quality gate (pass)