restructured manifest and plugins loading; updated plugins

plugins/youtube_download/yt_dlp/extractor/arcpublishing.py

@@ -62,6 +62,20 @@ class ArcPublishingIE(InfoExtractor):
         'url': 'arcpublishing:tronc:460f2931-8130-4719-8ea1-ffcb2d7cb685',
         'only_matching': True,
     }]
+    _WEBPAGE_TESTS = [{
+        'url': 'https://www.uppermichiganssource.com/2025/07/18/scattered-showers-storms-bring-heavy-rain-potential/',
+        'info_dict': {
+            'id': '508116f7-e999-48db-b7c2-60a04842679b',
+            'ext': 'mp4',
+            'title': 'Scattered showers & storms bring heavy rain potential',
+            'description': 'Scattered showers & storms bring heavy rain potential',
+            'duration': 2016,
+            'thumbnail': r're:https?://.+\.jpg',
+            'timestamp': 1752881287,
+            'upload_date': '20250718',
+        },
+        'expected_warnings': ['Ignoring subtitle tracks found in the HLS manifest'],
+    }]
     _POWA_DEFAULTS = [
         (['cmg', 'prisa'], '%s-config-prod.api.cdn.arcpublishing.com/video'),
         ([