feat(providers): detect HTML encoding before parsing

Add chardet-based _decode_html_content() to aniworld_provider. Apply
to all BeautifulSoup parsing calls to prevent decoding warnings on
pages with mismatched encoding declarations. Falls back to utf-8
with errors='replace' when confidence < 0.7.

Also fix test_enhanced_provider HLS test signature and add HLS
pattern unit tests.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

requirements.txt

@@ -22,6 +22,7 @@ APScheduler>=3.10.4
 Events>=0.5
 requests>=2.31.0
 beautifulsoup4>=4.12.0
+chardet>=5.2.0
 fake-useragent>=1.4.0
 yt-dlp>=2024.1.0
 urllib3>=2.0.0