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>

docs/DEVELOPMENT.md

@@ -342,6 +342,35 @@ Doodstream alternates between `dood.li`, `dood.so`, `dood.la`). Only the
 referer hints in `PROVIDER_HEADERS` are persisted — discovery still happens
 at runtime through AniWorld's redirect endpoint.
 
+### HLS Stream Handling
+
+HLS (HTTP Live Streaming) manifests (`.m3u8`) require yt-dlp to use the
+`ffmpeg` downloader with `--hls-use-mpegts`. Both providers configure this
+automatically:
+
+```python
+ydl_opts = {
+    "downloader": "ffmpeg",     # Use ffmpeg instead of native
+    "hls_use_mpegts": True,     # Write transport stream (.ts) segments
+}
+```
+
+**Why this matters**: Without ffmpeg, yt-dlp logs:
+`"Live HLS streams are not supported by the native downloader"`
+
+**Requirements**:
+- ffmpeg must be installed and in PATH (`which ffmpeg`)
+- Install: `apt install ffmpeg` (Debian/Ubuntu) or `brew install ffmpeg` (macOS)
+- Startup health check (see Health Check Endpoints) verifies ffmpeg presence
+
+**Trade-offs**:
+- HLS downloads are slower than direct MP4 (reassembly of .ts segments)
+- Requires more disk space during download
+- May need post-processing if .ts format is not desired
+
+**Detection**: VOE provider extracts HLS URLs via `HLS_PATTERN` regex. Other
+providers let yt-dlp auto-detect from URL/content-type.
+
 ### Updating yt-dlp
 
 When extractors break (typical symptoms: every provider HEAD probe succeeds