chore(viridian): update all Docker services to latest pinned releases

Update all container images to their latest stable releases with pinned
version tags (not "latest" tag for reproducibility).

Multimedia services:
- Jellyfin: 10.10.5 → 10.11.5
- Lidarr: 2.9.6.4552 → 3.1.0.4875
- Prowlarr: 1.30.2.4939 → 2.3.0.5236
- qBittorrent: 5.0.3 → 5.1.4
- Radarr: 5.18.4.9674 → 6.0.4.10291
- Sonarr: 4.0.13.2932 → 4.0.16.2944

Services:
- OpenGist: 1.10 → 1.11.1

nixos/viridian/services/opengist/default.nix

@@ -5,7 +5,7 @@ in {
   # OpenGist service configuration
   virtualisation.oci-containers.containers = {
     opengist = {
-      image = "ghcr.io/thomiceli/opengist:1.10";
+      image = "ghcr.io/thomiceli/opengist:1.11.1";
       ports = [
         "${port}:${port}"
       ];