Tag colour classes (bg-cyan-100, text-cyan-900, etc.) are generated
dynamically in TagMetadata.get_css_classes() in apps/blog/models.py.
Tailwind's content scanner only covered HTML templates, so these classes
were purged from the CSS build — rendering tags as white-on-white.
Add apps/blog/models.py to the Tailwind content array so the JIT
compiler detects and retains the dynamic colour classes.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>