Bug: Two get_by_cid methods existed in L1CacheManager. The second
definition shadowed the first, breaking recipe lookup because the
comprehensive method (using find_by_cid) was hidden.
- Remove duplicate get_by_cid method (lines 470-494)
- Add regression test to ensure only one get_by_cid exists
- Add tests for template variables and recipe visibility
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>