Create extractResourceOwnerAndBucket() helper to consolidate the repeated pattern
of unmarshaling metadata and extracting bucket name from resource path. This
pattern was duplicated in handleTagResource, handleListTagsForResource, and
handleUntagResource. Update all three handlers to use the helper.
Also update remaining uses of getPrincipalFromRequest() (in handler_bucket_create,
handler_bucket_get_list_delete, handler_namespace) to use getAccountID() after
consolidating the two identical methods.
Update handleListTagsForResource to fetch and pass bucket policy to
CheckPermission, matching the behavior of handleTagResource/handleUntagResource.
This enables bucket-policy-based permission grants to be evaluated for
ListTagsForResource, not just ownership-based checks.
Refactored resolveResourcePath to return resource type, enabling accurate
NoSuchBucket vs NoSuchTable error codes. Added existence checks before
deleting policies.
- Add authorization checks to all S3 Tables handlers (policy, table ops) to enforce security
- Improve error handling to distinguish between NotFound (404) and InternalError (500)
- Fix directory FileMode usage in filer_ops
- Improve test randomness for version tokens
- Update permissions comments to acknowledge IAM gaps
- Implement strict table name validation (prevention of path traversal and character enforcement)
- Add nil checks for entry.Entry in all listing loops to prevent panics
- Propagate backend errors instead of swallowing them or assuming 404
- Correctly map filer_pb.ErrNotFound to appropriate S3 error codes
- Standardize existence checks across bucket, namespace, and table handlers
