fix(review): resolve PR #244 review threads, harden markdown fence/asterisk parsing, and update release notes

[dan-petty]

Remediate the 6 unresolved review discussion threads on release PR #244:

1. Line-Start Fence Parser Hardening (pipeline.py): Replace literal backtick counting with line-start delimiter inspection to prevent inline code backticks from unbalancing fences.
2. Heading Asterisk Escaping (pipeline.py): Safely escape un-backticked asterisks in titles for headings and table rows.
3. Paired Bold Stripping (review_schema.py): Only strip double-asterisks when they form a matched outer pair, preserving Python unpacking like **kwargs.
4. Dynamic Version in Generator Test (test_instruction_generator.py): Use devops_cli.version instead of hardcoded version.
5. Comprehensive Release Notes (CHANGELOG.md): Document all v0.2.20 shipped deliverables.
6. Roadmap Claims Alignment (RELEASE_CYCLE.md): Verify canonical alignment with docs/ROADMAP.md.