Reorganize docker-compose stacks for better service grouping

Stack changes:
- Renamed media-extended.yml → media-management.yml (better clarity)
- Moved Plex from media → alternatives (Jellyfin is primary)
- Moved code-server from utilities → infrastructure
- Moved Sonarr, Radarr, Prowlarr from media → media-management
- Moved Calibre-web from media-management → media

New stack organization:
- media.yml (3): Jellyfin, Calibre-web, qBittorrent
- media-management.yml (13): All *arr apps, transcoders
- alternatives.yml (6): Plex, Portainer, Authentik
- infrastructure.yml (7): Added code-server
- utilities.yml (6): Removed code-server

Documentation updated:
- README.md: Updated stack descriptions
- services-overview.md: Updated service counts and locations
- All service docs: Updated file paths media-extended → media-management

tasks.txt

@@ -1,3 +1,9 @@
-getting-started.md
-    Getting Started Checklist
-      include clone repository as first step
+reorganize the media stack
+  move plex to alternatives
+  move calibre-web from media-extended
+  move all the arr apps to the media-extended folder
+
+rename media-extended stack to media-management
+
+move code-server to infrastructure
+