prepare fastapi root layout for server deployment

.gitignore

@@ -10,6 +10,7 @@ htmlcov/
 .venv/
 venv/
 backend/.venv/
+/backend/
 
 # Node / frontend
 frontend/
@@ -22,6 +23,7 @@ frontend/*.tsbuildinfo
 .env
 .env.*
 !.env.example
+!.env.production.example
 
 # Local runtime data and generated artifacts
 storage/
@@ -37,7 +39,8 @@ uploads/
 # Demo-only or temporary files
 docs/
 demo_frontend/
-/scripts/
+scripts/check_mysql_demo.ps1
+scripts/init_mysql_demo.ps1
 backend/test*.sql
 
 # Editor / OS