Refine .env.example files across all stacks

- Streamline variable organization and formatting
- Reduce redundant comments and improve clarity
- Maintain all required variables for each stack

docker-compose/homeassistant/.env.example

@@ -1,6 +1,8 @@
 # Home Assistant Stack Environment Variables
-# These variables are used for Home Assistant and related services
 
-# Base Configuration
-DOMAIN=
 TZ=
+PUID=
+PGID=
+SERVER_IP=
+SERVER_HOSTNAME=
+DOMAIN=