Fix remaining volume mount paths in stack configs

- Update Vikunja config path to remove swarm-production subdirectory
- Fix rsync source path to backup appdata instead of backups directory
- Update rsync excludes path to correct location in projects directory

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

stacks/apps/vikunja/stack.yml

@@ -24,7 +24,7 @@ services:
       - vikunja-jwt
     volumes:
       - /home/doc/projects/swarm-data/appdata/vikunja/files:/app/vikunja/files
-      - /home/doc/projects/swarm/swarm-production/stacks/apps/vikunja/config.yml:/etc/vikunja/config.yml:ro
+      - /home/doc/projects/swarm/stacks/apps/vikunja/config.yml:/etc/vikunja/config.yml:ro
     networks:
       - homelab
     # healthcheck: