feat(bundle): export review artifact bundle

[MMoney1988]

Summary

Adds a static review bundle export that writes existing PQR review artifacts into one folder.

Why

PQR now produces several review artifacts separately. This PR adds a packaging layer so reviewers can receive one deterministic folder without running every export command individually.

What

• Adds pdf_quality_report.review_bundle and the pdf-quality-review-bundle entry point.
• Writes README.md, quality_report.md, review_findings.md, output.md, chunk_records.jsonl, and chunk_review.md into an output directory.
• Reuses existing renderers and exporters; no new checks or decision logic.
• Documents the bundle command, file list, exit behavior, and boundaries.

Tests

• .venv/bin/python -m pytest -p no:cacheprovider tests -> 116 passed
• .venv/bin/python -m ruff check src tests -> passed
• git diff --check -> passed
• .venv/bin/python -m pdf_quality_report.review_bundle --help -> passed
• .venv/bin/pdf-quality-review-bundle --help -> passed
• Module and installed-entry-point bundle smokes for page 012 -> passed

Risks

• The bundle command exits 0 when files are written, even if the quality report decision is REVIEW or BLOCK; this is documented.
• Known bundle files are overwritten, while unrelated output-directory files are preserved.
• No source PDF, normalized_blocks copy, workflow queue, ZIP, manifest schema, or readiness claim is introduced.

Rollback

Revert this PR to remove the bundle CLI, module, tests, and docs. Existing report, findings, Markdown, chunk, and chunk-review exports remain unaffected.