feat(helm): expose the transcode session retention window

The chart sets the lease duration but not the retention window that keeps an
orphaned session record available for takeover.

- add ha.transcodeStore.sessionRetentionSeconds and pass it to the statefulset

deploy/helm/jellyfin-ha/templates/statefulset.yaml

@@ -168,6 +168,8 @@ spec:
             {{- end }}
             - name: Jellyfin__TranscodeStore__LeaseDurationSeconds
               value: {{ .Values.ha.transcodeStore.leaseDurationSeconds | quote }}
+            - name: Jellyfin__TranscodeStore__SessionRetentionSeconds
+              value: {{ .Values.ha.transcodeStore.sessionRetentionSeconds | quote }}
             {{- end }}
 
             # ---------------------------------------------------------------------------

deploy/helm/jellyfin-ha/values.yaml

@@ -45,6 +45,9 @@ ha:
     # -- How long (seconds) a pod's transcode lease is valid before another pod may take over.
     leaseDurationSeconds: 30
 
+    # -- How long (seconds) an unrenewed session record is kept so another pod can still take it over.
+    sessionRetentionSeconds: 300
+
     # -- Secret containing the Redis connection string.
     # If set, the connection string is read from this secret instead of the value above.
     # The secret must have a key named by existingSecret.key.