Improve AdLint demo path

[ftchvs]

Summary

• Add adlint demo with an embedded public-safe synthetic sample so visitors can run a useful demo without preparing a config file.
• Add make demo and update README quick-start/demo paths.
• Improve health-claim demo rewrites so the first suggested rewrite is cleaner.
• Add package metadata, project URLs, keywords, and classifiers.
• Refresh eval report counts/baselines and remove private local path references from paper visual QA docs.

Verification

• make test
• make demo
• make pr-preflight
• make real-cases-ci
• make real-world-blind-ci
• git diff --check
• private path/token scan