feat(k8s/jellyfin): add Jellyfin stack (deployment scaled to 0 for data migration)

Jellyfin media server with Intel GPU hardware transcoding, NFS media
volume, and UDP discovery/DLNA ports. OIDC auth handled internally
by Jellyfin (no Authelia middleware on ingress).

kubernetes/app/jellyfin/networkpolicy.yaml

@@ -0,0 +1,47 @@
+# Default deny all ingress in the jellyfin namespace
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: default-deny-ingress
+  namespace: jellyfin
+spec:
+  podSelector: {}
+  policyTypes:
+    - Ingress
+---
+# Allow Traefik ingress controller to reach Jellyfin
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: allow-ingress-controller
+  namespace: jellyfin
+spec:
+  podSelector:
+    matchLabels:
+      app: jellyfin
+  policyTypes:
+    - Ingress
+  ingress:
+    - from:
+        - namespaceSelector:
+            matchLabels:
+              kubernetes.io/metadata.name: traefik
+---
+# Allow UDP discovery and DLNA from local network
+apiVersion: networking.k8s.io/v1
+kind: NetworkPolicy
+metadata:
+  name: allow-udp-discovery
+  namespace: jellyfin
+spec:
+  podSelector:
+    matchLabels:
+      app: jellyfin
+  policyTypes:
+    - Ingress
+  ingress:
+    - ports:
+        - port: 7359
+          protocol: UDP
+        - port: 1900
+          protocol: UDP