fix: remove minify plugin to resolve build issues

The mkdocs-minify-plugin with htmlmin was causing segfaults during the
properdocs build when processing the large i18n file set.

Changes:
- Removed mkdocs-minify-plugin from requirements.txt
- Removed htmlmin2 dependency
- Removed minify plugin from mkdocs_template.yml
- Regenerated properdocs.yml

Verification:
- Docker build: SUCCESS ✓
- Image loading: HTTP 200 ✓
- i18n functionality: Working ✓

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>