Add stack-type=dev-only labels to dev stacks

Label stacks that should only run on ubuntu-dev:
- bookclub, dockge, filebrowser, meshmon, meshtastic-web
- mllogwatcher, network-mcp, obby, obsidian-tools
- syncthing, szurubooru

These will now be filtered by the updated workflow.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

stacks/meshtastic-web/docker-compose.yml

@@ -5,3 +5,5 @@ services:
     restart: unless-stopped
     ports:
       - "8585:8080"
+    labels:
+      - "com.ghost.tel/stack-type=dev-only"