🔧 fix: revert Bulma submodule to 0.9.4 for v2.7.1 compatibility

Fixes collectstatic failure in v2.7.0 by reverting Bulma from 1.0.4 back to 0.9.4.

The v2.7.0 release accidentally updated Bulma to 1.0.4 which uses _index.scss files,
but the Python code still expected _all.sass files from Bulma 0.9.x. This caused
collectstatic to fail with 'File to import not found' errors.

This patch release (v2.7.1) maintains Django 5.2 compatibility while fixing the
Bulma version mismatch by using the same Bulma 0.9.4 that v2.6.0 used successfully.

Resolves #123

Author: lemonsaurus