fix(yazi): previewer match field name -> url (yazi 26.x)

yazi 26.x renamed the previewer/fetcher match key from name to url. The
fetchers were updated but the markdown previewer still used name, so the
whole [plugin] config failed to parse ("at least one of 'url' or 'mime'
must be specified") and yazi fell back to its presets.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

modules/home/yazi.nix

@@ -56,8 +56,12 @@ in
           # Route only audio + subtitles to mediainfo's text metadata;
           # images/videos keep yazi's native visual thumbnails. Markdown
           # renders through glow.
+          # Match field is `url` (a path glob) or `mime` — yazi 26.x renamed
+          # the old `name` to `url`, same as the fetchers above. Using `name`
+          # fails the parse ("at least one of 'url' or 'mime'") and yazi falls
+          # back to its presets.
           prepend_previewers = [
-            { name = "*.md"; run = "glow"; }
+            { url = "*.md"; run = "glow"; }
             { mime = "audio/*"; run = "mediainfo"; }
             { mime = "application/subrip"; run = "mediainfo"; }
           ];