Remove deprecated allowEmptyFolder CLI option

The allowEmptyFolder option is no longer functional because:
1. The code that used it was already commented out
2. Empty folder cleanup is now handled asynchronously by EmptyFolderCleaner

The CLI flags are kept for backward compatibility but marked as deprecated
and ignored. This removes:
- S3ApiServerOption.AllowEmptyFolder field
- The actual usage in s3api_object_handlers_list.go
- Helm chart values and template references
- References in test Makefiles and docker-compose files

k8s/charts/seaweedfs/templates/all-in-one/all-in-one-deployment.yaml

@@ -246,11 +246,6 @@ spec:
               -s3.cert.file=/usr/local/share/ca-certificates/client/tls.crt \
               -s3.key.file=/usr/local/share/ca-certificates/client/tls.key \
               {{- end }}
-              {{- if ne .Values.allInOne.s3.allowEmptyFolder nil }}
-              -s3.allowEmptyFolder={{ .Values.allInOne.s3.allowEmptyFolder }} \
-              {{- else if ne .Values.s3.allowEmptyFolder nil }}
-              -s3.allowEmptyFolder={{ .Values.s3.allowEmptyFolder }} \
-              {{- end }}
               {{- if or .Values.allInOne.s3.enableAuth .Values.s3.enableAuth .Values.filer.s3.enableAuth }}
               -s3.config=/etc/sw/s3/seaweedfs_s3_config \
               {{- end }}

k8s/charts/seaweedfs/templates/filer/filer-statefulset.yaml

@@ -213,9 +213,6 @@ spec:
               -s3.cert.file=/usr/local/share/ca-certificates/client/tls.crt \
               -s3.key.file=/usr/local/share/ca-certificates/client/tls.key \
               {{- end }}
-              {{- if eq (typeOf .Values.filer.s3.allowEmptyFolder) "bool" }}
-              -s3.allowEmptyFolder={{ .Values.filer.s3.allowEmptyFolder }} \
-              {{- end }}
               {{- if .Values.filer.s3.enableAuth }}
               -s3.config=/etc/sw/seaweedfs_s3_config \
               {{- end }}

k8s/charts/seaweedfs/templates/s3/s3-deployment.yaml

@@ -143,9 +143,6 @@ spec:
               {{- if .Values.s3.domainName }}
               -domainName={{ .Values.s3.domainName }} \
               {{- end }}
-              {{- if eq (typeOf .Values.s3.allowEmptyFolder) "bool" }}
-              -allowEmptyFolder={{ .Values.s3.allowEmptyFolder }} \
-              {{- end }}
               {{- if .Values.s3.enableAuth }}
               -config=/etc/sw/seaweedfs_s3_config \
               {{- end }}

k8s/charts/seaweedfs/values.yaml

@@ -856,8 +856,6 @@ filer:
     port: 8333
     # add additional https port
     httpsPort: 0
-    # allow empty folders
-    allowEmptyFolder: false
     # Suffix of the host name, {bucket}.{domainName}
     domainName: ""
     # enable user & permission to s3 (need to inject to all services)
@@ -885,8 +883,6 @@ s3:
   httpsPort: 0
   metricsPort: 9327
   loggingOverrideLevel: null
-  # allow empty folders
-  allowEmptyFolder: true
   # enable user & permission to s3 (need to inject to all services)
   enableAuth: false
   # set to the name of an existing kubernetes Secret with the s3 json config file
@@ -1133,7 +1129,6 @@ allInOne:
     port: null  # S3 gateway port (null inherits from s3.port)
     httpsPort: null  # S3 gateway HTTPS port (null inherits from s3.httpsPort)
     domainName: null  # Suffix of the host name (null inherits from s3.domainName)
-    allowEmptyFolder: null  # Allow empty folders in S3 (null inherits from s3.allowEmptyFolder)
     enableAuth: false  # Enable user & permission to S3
     # Set to the name of an existing kubernetes Secret with the s3 json config file
     # should have a secret key called seaweedfs_s3_config with an inline json config