Fix: Rename directory to remove & character causing shell issues

Renamed ebook_backend&admin_panel to ebook_backend_admin_panel
  The & character was being interpreted by shell as background
  process operator, causing 'Dockerfile not found' errors in Coolify.

ebook_backend_admin_panel/requirements.txt

@@ -0,0 +1,16 @@
+fastapi
+uvicorn
+sqlalchemy
+passlib[bcrypt]
+bcrypt==4.0.1
+python-jose[cryptography]
+pydantic
+python-multipart
+flask
+psycopg2-binary
+itsdangerous
+pytest
+httpx
+pytest-postgresql
+pytz
+python-dotenv==1.0.0