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/transcoders/.env.example

@@ -1,15 +1,12 @@
 # Transcoders Stack Environment Variables
-# These variables are used for Tdarr, Unmanic
 
-# Base Configuration
-DOMAIN=
 TZ=
-
-# User Configuration
 PUID=
 PGID=
+SERVER_IP=
+SERVER_HOSTNAME=
+DOMAIN=
 
-# Directory Configuration
 MEDIA_DIR=
 TDARR_TRANSCODE_DIR=
 UNMANIC_TRANSCODE_DIR=