Fix web/ startup errors and sync with boilerplate

- Load .env via python-dotenv in core.py
- Skip analytics DB open if file doesn't exist
- Guard dashboard analytics calls when DB not available
- Namespace admin templates under admin/ to avoid blueprint conflicts
- Add dev-login routes for user and admin (DEBUG only)
- Update .copier-answers.yml src_path to GitLab remote

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

web/.gitignore

@@ -35,3 +35,7 @@ htmlcov/
 dist/
 build/
 *.egg-info/
+
+# Tailwind CSS
+bin/
+src/beanflows/static/css/output.css