fix(content): author rendered as J, o, h, n, J, e, o, n, g on mac-productivity-apps (#5184)

Frontmatter had the author serialized character-by-character as a YAML
list of 10 single-char strings. Zod's z.array(z.string()) accepted it,
and the page renderer joined them with commas. Replaced with the
scalar 'John Jeong'.

Co-authored-by: Cortana <cortana@fastrepl.com>

Author: ComputelessComputer

apps/web/content/articles/mac-productivity-apps.mdx

@@ -1,17 +1,7 @@
 ---
 meta_title: "9 Best Mac Productivity Apps for 2026"
 meta_description: "Discover the best Mac productivity apps for 2026. A vetted list of tools for AI meeting notes, file management, and automation."
-author:
-  - "J"
-  - "o"
-  - "h"
-  - "n"
-  - " "
-  - "J"
-  - "e"
-  - "o"
-  - "n"
-  - "g"
+author: "John Jeong"
 featured: true
 category: "Guides"
 date: "2026-02-13"