doc: add s3.bucket.access command documentation

Document the new weed shell command for configuring anonymous bucket
access. Add to S3 Bucket Policies page and shell command listing.

S3-Bucket-Policies.md

@@ -6,6 +6,33 @@ SeaweedFS supports AWS S3-compatible bucket policies for controlling access to b
 
 Bucket policies allow you to grant or deny permissions for S3 operations on a bucket and its objects. They are resource-based policies that complement user-level IAM policies.
 
+## Quick Setup with Weed Shell
+
+The `s3.bucket.access` shell command provides a simple way to configure anonymous access without external tools.
+
+```bash
+# View current anonymous access policy
+> s3.bucket.access -name my-bucket
+
+# Grant anonymous read and list access (public download)
+> s3.bucket.access -name my-bucket -access read,list
+
+# Grant full anonymous access
+> s3.bucket.access -name my-bucket -access read,write,list
+
+# Remove all anonymous access (make private)
+> s3.bucket.access -name my-bucket -access none
+```
+
+Supported permissions: `read` (GetObject), `write` (PutObject, DeleteObject, multipart), `list` (ListBucket).
+
+The command writes a standard bucket policy with `Principal: "*"`. Other (non-anonymous) policy statements are preserved when changing access.
+
+**Note:** Anonymous access also requires an `anonymous` identity in IAM. Create one via the admin UI or:
+```bash
+> s3.configure -user=anonymous -actions=Read,List -apply
+```
+
 ## AWS CLI Setup
 
 First, configure the AWS CLI to connect to your SeaweedFS S3 endpoint:

weed-shell.md

@@ -52,8 +52,9 @@ Type:	"help <command>" for help on <command>. Most commands support "<command> -
   remote.mount.buckets          	# mount all buckets in remote storage and pull its metadata 
   remote.uncache                	# keep the metadata but remote cache the file content for mounted directories or files 
   remote.unmount                	# unmount remote storage 
-  s3.bucket.create              	# create a bucket with a given name 
-  s3.bucket.delete              	# delete a bucket by a given name 
+  s3.bucket.access              	# view or change the anonymous access policy of an S3 bucket
+  s3.bucket.create              	# create a bucket with a given name
+  s3.bucket.delete              	# delete a bucket by a given name
   s3.bucket.list                	# list all buckets 
   s3.bucket.lock                	# view or enable Object Lock for an S3 bucket 
   s3.bucket.owner               	# view or change the owner of an S3 bucket