test: add comprehensive integration test suite
Add 9 integration test modules covering:
- End-to-end data flow pipeline
- Lens transformation chains
- Local storage workflows
- Atmosphere ATProto workflows
- Cross-backend interoperability
- Promotion pipeline (local to atmosphere)
- Dynamic type loading from schemas
- Error handling and recovery
- Edge cases and data type coverage
Also document chainlink issue tracking usage in CLAUDE.md.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>