test(persistence): add comprehensive cache volume tests

Add helm-unittest tests for dedicated cache volume persistence:
- Default emptyDir behavior
- PVC creation when enabled
- hostPath configuration
- Volume mount verification
- PVC size, access mode, storage class configuration
- Annotations support
- Existing claim usage
- Type-specific behavior (pvc vs hostPath vs emptyDir)

Add NOTES.txt with persistence information:
- Show config, media, and cache volume types
- Display cache volume details when enabled
- Benefits explanation for cache volume
- Warning for hostPath usage

Tests ensure cache persistence works correctly for all scenarios.

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

charts/jellyfin/tests/cache_persistence_test.yaml

@@ -0,0 +1,160 @@
+suite: test cache persistence
+templates:
+  - deployment.yaml
+  - persistentVolumeClaim.yaml
+tests:
+  # Deployment volume mount tests
+  - it: should mount cache as emptyDir by default
+    template: deployment.yaml
+    asserts:
+      - contains:
+          path: spec.template.spec.volumes
+          content:
+            name: cache
+            emptyDir: {}
+
+  - it: should mount cache PVC when enabled
+    template: deployment.yaml
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: pvc
+    asserts:
+      - contains:
+          path: spec.template.spec.volumes
+          content:
+            name: cache
+            persistentVolumeClaim:
+              claimName: RELEASE-NAME-jellyfin-cache
+
+  - it: should mount cache from hostPath when configured
+    template: deployment.yaml
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: hostPath
+      persistence.cache.hostPath: /mnt/jellyfin-cache
+    asserts:
+      - contains:
+          path: spec.template.spec.volumes
+          content:
+            name: cache
+            hostPath:
+              path: /mnt/jellyfin-cache
+
+  - it: should mount cache at correct path
+    template: deployment.yaml
+    asserts:
+      - contains:
+          path: spec.template.spec.containers[0].volumeMounts
+          content:
+            name: cache
+            mountPath: /cache
+
+  # PVC tests
+  - it: should not create cache PVC by default
+    template: persistentVolumeClaim.yaml
+    asserts:
+      - hasDocuments:
+          count: 2  # config and media only
+
+  - it: should create cache PVC when enabled
+    template: persistentVolumeClaim.yaml
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: pvc
+    asserts:
+      - hasDocuments:
+          count: 3  # config, media, and cache
+      - contains:
+          path: metadata.name
+          content: RELEASE-NAME-jellyfin-cache
+
+  - it: should not create cache PVC when type is hostPath
+    template: persistentVolumeClaim.yaml
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: hostPath
+    asserts:
+      - hasDocuments:
+          count: 2  # config and media only
+
+  - it: should not create cache PVC when type is emptyDir
+    template: persistentVolumeClaim.yaml
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: emptyDir
+    asserts:
+      - hasDocuments:
+          count: 2
+
+  - it: should set cache PVC size correctly
+    template: persistentVolumeClaim.yaml
+    documentIndex: 2
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: pvc
+      persistence.cache.size: 20Gi
+    asserts:
+      - equal:
+          path: spec.resources.requests.storage
+          value: 20Gi
+
+  - it: should set cache PVC access mode
+    template: persistentVolumeClaim.yaml
+    documentIndex: 2
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: pvc
+      persistence.cache.accessMode: ReadWriteMany
+    asserts:
+      - contains:
+          path: spec.accessModes
+          content: ReadWriteMany
+
+  - it: should set cache PVC storage class
+    template: persistentVolumeClaim.yaml
+    documentIndex: 2
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: pvc
+      persistence.cache.storageClass: fast-ssd
+    asserts:
+      - equal:
+          path: spec.storageClassName
+          value: fast-ssd
+
+  - it: should add annotations to cache PVC
+    template: persistentVolumeClaim.yaml
+    documentIndex: 2
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: pvc
+      persistence.cache.annotations:
+        my-annotation: my-value
+    asserts:
+      - equal:
+          path: metadata.annotations.my-annotation
+          value: my-value
+
+  - it: should use existing claim when specified
+    template: deployment.yaml
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: pvc
+      persistence.cache.existingClaim: my-existing-cache-claim
+    asserts:
+      - contains:
+          path: spec.template.spec.volumes
+          content:
+            name: cache
+            persistentVolumeClaim:
+              claimName: my-existing-cache-claim
+
+  - it: should not create PVC when existing claim used
+    template: persistentVolumeClaim.yaml
+    set:
+      persistence.cache.enabled: true
+      persistence.cache.type: pvc
+      persistence.cache.existingClaim: my-existing-cache-claim
+    asserts:
+      - hasDocuments:
+          count: 2  # config and media only, not cache