test: add basic tests for cache-search & network fetchers

test: enable debug
test: add pytest.ini to mark tests that require network
fix: cache-search should not aquire full match of artists due to different translations
fix: replace dynamic f-string SQL in track WHERE clauses with parameterized nullable conditions
refactor: lrc.py should never directly call print, return a str instead
chore: add requirements.txt (via 'uv export')
chore: update README.md with dev instructions

tests/test_cache.py

@@ -289,7 +289,6 @@ def test_search_by_meta_fuzzy_rules_and_duration_sorting(cache_db: CacheEngine)
     )
 
     rows = cache_db.search_by_meta(
-        artist="Ｂ ; A",
         title="  hello world  ",
         length=200000,
     )