Phase 0: Push test coverage from 92.1% to 100% by adding catalog_test.go
and targeted tests for all uncovered branches in search.go. Add
BenchmarkSearch with 150 topics (~745us/op baseline).
Phase 1: Implement three search improvements:
- Levenshtein-based fuzzy matching (max distance 2, words >= 3 chars)
- Quoted phrase search via extractPhrases() with +8.0 boost
- Tag boost (+3.0) and multi-word bonus (+2.0) scoring
- Named scoring constants replacing magic numbers
All changes are backward-compatible; Search() signature unchanged.
Co-Authored-By: Charon <developers@lethean.io>
