Add 100+ test cases covering all normalization scenarios:
- Empty/nil inputs, whitespace trimming
- Titlecasing with hyphens, apostrophes, multi-word tags
- Punctuation preference (hyphens, periods, apostrophes)
- Case-insensitive deduplication with and without punctuation
- Contributor case preservation (CAPSLOCK, Title Case, lowercase)
- Edge cases: only punctuation, multiple spaces, mixed content
New test scenarios for punctuation preference:
- Prefer "Science-Fiction" over "science fiction"
- Prefer "O'Reilly Media" over "OReilly Media"
- Prefer "ACME CORP." over "acme corp"
- Test deduplication when punctuated version appears later in array
All tests passing ✓
Relates to Tags & Contributors Migration Phase 4
john-okeefe
08e823d6ab