feat(pdftract-64p5): implement classify CLI subcommand structure
Add the `pdftract classify` CLI subcommand with proper argument parsing,
feature gates, and path traversal protection. Add `--auto` flag to extract
subcommand.
Implementation details:
- Add Classify subcommand with --profiles DIR, --pretty, --top-k, --exit-on-unknown
- Implement path traversal protection for --profiles DIR
- Add --auto flag to Extract subcommand
- Feature-gate classify command behind `profiles` feature
- Create classify.rs module with ClassificationOutput struct
- Add unit tests for JSON serialization
Limitations deferred to bead 5.6.4:
- Built-in profiles (load_builtins() not yet available)
- YAML profile loading (requires YAML-to-Profile parsing)
- Full classification pipeline (awaits profile infrastructure)
Closes: pdftract-64p5
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
a0f01977a1