Update docker-compose files to use configurable environment variables

- Replace hardcoded paths with variables: STACKS_DIR, PROJECTS_DIR, MEDIA_DIR, DOWNLOAD_DIR
- Update .env.example with new variable definitions
- Remove unused .template files
- Enable configurable directory paths for stacks, media, and downloads

docker-compose/core/duckdns/logrotate.conf

@@ -1,5 +0,0 @@
-/config/duck.log {
-    rotate 5
-    size 100k
-    compress
-}