fix(blog): correct conversation tag from Mara to Cadey in Paranoid NixOS Setup post

[Xe]

Summary

• Fixed conversation tag from "Mara" to "Cadey" in the Paranoid NixOS Setup blog post
• This resolves the broken sticker image that was showing "mara/enby" instead of "cadey/enby"

Test plan

• Verify the blog post renders correctly with the updated conversation tag
• Check that the sticker URL now points to the correct character

This fix addresses the issue described in SITE-8 where the conversation sticker was not found due to the incorrect character name.

[linear]

SITE-8 Missing image on "Paranoid NixOS Setup" blog post