feat(streaming): jellyfin GPU CDI access and jellyplex token

Decode-only P100 access for trickplay. Gives jellyplex-watched its
Jellyfin API key (still DRYRUN=True until mapping verified).

stacks/streaming/docker-compose.yml

@@ -23,6 +23,8 @@ services:
     networks: [streaming, edge]
     env_file:
       - stack.env
+    devices:
+      - nvidia.com/gpu=0
     environment:
       - JELLYFIN_PublishedServerUrl=https://jellyfin.ginnoir.com
     volumes: