feat(persistence): add cache volume persistence support

Add dedicated cache volume configuration to reduce wear on SD cards and improve
performance by allowing cache to be stored on separate storage.

Changes:
- Add persistence.cache configuration in values.yaml with support for:
  - PVC (default type when enabled)
  - hostPath for direct host mount
  - emptyDir (default when disabled)
- Add cache volume mount at /cache in deployment
- Add cache PersistentVolumeClaim template
- Support for existing PVC via existingClaim
- Configurable size (default 10Gi), accessMode, storageClass, and annotations
- Update Chart version from 2.5.0 to 2.5.1
- Add Artifact Hub changelog annotation

The cache volume is disabled by default to maintain backward compatibility.
Users can enable it via:

```yaml
persistence:
  cache:
    enabled: true
    type: pvc
    size: 10Gi
```

This addresses the use case mentioned in #62 where users want to avoid SD card
wear by storing cache on separate persistent storage.

Fixes: #62

Co-Authored-By: Claude <noreply@anthropic.com>
Signed-off-by: Aleksei Sviridkin <f@lex.la>

charts/jellyfin/templates/deployment.yaml

@@ -119,6 +119,8 @@ spec:
               name: config
             - mountPath: /media
               name: media
+            - mountPath: /cache
+              name: cache
             {{- with .Values.volumeMounts }}
             {{- toYaml . | nindent 12 }}
             {{- end }}
@@ -152,6 +154,21 @@ spec:
           {{- else }}
           emptyDir: {}
           {{- end }}
+        - name: cache
+          {{- if .Values.persistence.cache.enabled }}
+            {{- if eq .Values.persistence.cache.type "pvc" }}
+          persistentVolumeClaim:
+            claimName: {{ if .Values.persistence.cache.existingClaim }}{{ .Values.persistence.cache.existingClaim }}{{- else }}{{ template "jellyfin.fullname" . }}-cache{{- end }}
+            {{- else if eq .Values.persistence.cache.type "hostPath" }}
+          hostPath:
+            path: {{ .Values.persistence.cache.hostPath }}
+            type: Directory
+            {{- else }}
+          emptyDir: {}
+            {{- end }}
+          {{- else }}
+          emptyDir: {}
+          {{- end }}
         {{- with .Values.volumes }}
         {{- toYaml . | nindent 8 }}
         {{- end }}

charts/jellyfin/templates/persistentVolumeClaim.yaml

@@ -43,3 +43,26 @@ spec:
   storageClassName: {{ . | quote }}
   {{- end }}
 {{- end }}
+
+{{- if and .Values.persistence.cache.enabled (eq .Values.persistence.cache.type "pvc") (not .Values.persistence.cache.existingClaim) }}
+---
+apiVersion: v1
+kind: PersistentVolumeClaim
+metadata:
+  name: {{ include "jellyfin.fullname" . }}-cache
+  labels:
+    {{- include "jellyfin.labels" . | nindent 4 }}
+  {{- with .Values.persistence.cache.annotations }}
+  annotations:
+    {{- toYaml . | nindent 4 }}
+  {{- end }}
+spec:
+  accessModes:
+    - {{ .Values.persistence.cache.accessMode | quote }}
+  resources:
+    requests:
+      storage: {{ .Values.persistence.cache.size | quote }}
+  {{- with .Values.persistence.cache.storageClass }}
+  storageClassName: {{ . | quote }}
+  {{- end }}
+{{- end }}