fix: use modern Hugo services.disqus config format

- Replace deprecated disqusShortname with services.disqus.shortname
- This is required for Hugo to properly detect and load Disqus

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

Author: tonykay

config/_default/config.toml

@@ -1,9 +1,12 @@
 title                 = "Spec Coding"
 languageCode          = "en-us"
 theme                 = ["github.com/chipzoller/hugo-clarity"]
-disqusShortname       = "disqus_YWibv6kNhd"
 googleAnalytics       = "" # Enable Google Analytics by entering your tracking id
 
+[services]
+  [services.disqus]
+    shortname = "disqus_YWibv6kNhd"
+
 [params]
   [params.author]
     name = "Spec Coding"