[hentaifoundry] extract 'categories' metadata (#8656)

* [hentaifoundry] Add support for categories
* rename 'hf_categories' to 'categories'
* move code into '_extract_categories()' method
* update tests

---------

Co-authored-by: Mike Fährmann <mike_faehrmann@web.de>

test/results/hentaifoundry.py

@@ -90,6 +90,7 @@ __tests__ = (
     "#sha1_content": "91bf01497c39254b6dfb234a18e8f01629c77fd1",
 
     "artist"     : "Tenpura",
+    "categories" : ["Anime & Manga"],
     "date"       : "dt:2016-02-22 14:41:19",
     "description": "Thank you!",
     "height"     : 700,
@@ -120,6 +121,7 @@ __tests__ = (
     "#results" : "https://pictures.hentai-foundry.com/s/Soloid/186714/Soloid-186714-Osaloop.swf",
 
     "artist"     : "Soloid",
+    "categories" : ["Misc"],
     "date"       : "dt:2013-02-07 17:25:54",
     "description": "It took me ages.\nI hope you'll like it.\nSorry for the bad quality, I made it on after effect because Flash works like shit when you have 44 layers to animate, and the final ae SWF file is 55mo big.",
     "extension"  : "swf",
@@ -204,22 +206,24 @@ Sorry for the bad quality, I made it on after effect because Flash works like sh
 {
     "#url"     : "https://www.hentai-foundry.com/stories/user/Likelymouse",
     "#class"   : hentaifoundry.HentaifoundryStoriesExtractor,
+    "#range"   : "2",
     "#results" : "https://www.hentai-foundry.com/stories/user/Likelymouse/77892/The-Sweater-and-Scarf-Public-Investigators-Part-1.pdf",
 
     "author"     : "Likelymouse",
-    "chapters"   : 4,
+    "categories" : ["Original", "Neko Shoujo & Kemonomimi"],
+    "chapters"   : 11,
     "comments"   : 0,
-    "date"       : "dt:2025-09-01 00:00:00",
+    "date"       : "dt:2025-10-04 00:00:00",
     "extension"  : "pdf",
     "filename"   : "The-Sweater-and-Scarf-Public-Investigators-Part-1",
     "index"      : 77892,
     "rating"     : 0,
     "src"        : "https://www.hentai-foundry.com/stories/user/Likelymouse/77892/The-Sweater-and-Scarf-Public-Investigators-Part-1.pdf",
-    "status"     : "Incomplete",
+    "status"     : "Complete",
     "title"      : "The Sweater and Scarf Public Investigators, Part 1",
     "user"       : "Likelymouse",
     "views"      : range(100, 10_000),
-    "words"      : 10661,
+    "words"      : 47031,
     "description": """\
 <div style="text-align:center"><a href="https://imgur.com/a/uRDss5c"><img src="https://i.imgur.com/SCWI09e.jpeg" alt="135x240"/></a><br />
 <br />
@@ -250,6 +254,7 @@ Follow 22 y/o Puffy Penelope as she descends into degeneracy, mastering her new
     "#sha1_url": "5a67cfa8c3bf7634c8af8485dd07c1ea74ee0ae8",
 
     "title": "Overwatch High Chapter Voting Location",
+    "categories": ["Games", "Overwatch"],
 },
 
 )