Classify a filer error before a user-controlled path is wrapped into it (#11004)

* util, pb: classify a filer error by the status the server sent

DoSeaweedListWithSnapshot wrapped a failed ListEntries with %v, dropping the
gRPC status, so IsTransientError fell back to matching substrings against a
message that now held the caller's path. Keep the status with %w and let it
decide, reading the server's own text rather than the wrapper's.

Claude-Session: https://claude.ai/code/session_01BjDWtZsCoZY6x4pdDmGWxU

* s3: keep the bucket and prefix out of the list retry decision

A bucket named transport, or a prefix under logs/unavailable/, made a
PermissionDenied listing look transient and got it retried; a key holding the
not-found sentence suppressed a retry that should have run. Both checks now
read the filer's status, and only fall back to the text when there is none.

Claude-Session: https://claude.ai/code/session_01BjDWtZsCoZY6x4pdDmGWxU

* filer, s3: classify a delete failure before the path is wrapped into it

The filer put the non-empty-folder marker behind its own "delete directory %s"
wrapper and the gateway matched it as a substring, so a key named after the
marker turned a real delete failure into the demote-the-marker no-op and the
request answered 204. Keep the marker leading the message that crosses the
wire, turn it back into a sentinel where the response is read, and match that.

Claude-Session: https://claude.ai/code/session_01BjDWtZsCoZY6x4pdDmGWxU

weed/s3api/s3api_object_versioning.go

@@ -1657,8 +1657,8 @@ func (s3a *S3ApiServer) updateLatestVersionAfterDeletion(ctx context.Context, bu
 		// Two ways rm can fail here: "non-empty folder" (orphan entries
 		// blocking the teardown — fall through to pointer clear) and a
 		// transient filer error (worth retrying). Distinguish by the
-		// canonical error substring; if we can't tell, treat as transient.
-		if strings.Contains(rmErr.Error(), filer.MsgFailDelNonEmptyFolder) {
+		// sentinel; if we can't tell, treat as transient.
+		if errors.Is(rmErr, filer.ErrNonEmptyFolder) {
 			glog.V(2).Infof("updateLatestVersionAfterDeletion: .versions/ for %s/%s still has orphan entries: %v", bucket, object, rmErr)
 			s3a.clearStaleLatestVersionPointer(bucket, object, bucketDir, versionsObjectPath, versionsEntry, "updateLatestVersionAfterDeletion")
 			return nil
@@ -1673,7 +1673,7 @@ func (s3a *S3ApiServer) updateLatestVersionAfterDeletion(ctx context.Context, bu
 		if retryErr == nil {
 			return nil
 		}
-		if strings.Contains(retryErr.Error(), filer.MsgFailDelNonEmptyFolder) {
+		if errors.Is(retryErr, filer.ErrNonEmptyFolder) {
 			s3a.clearStaleLatestVersionPointer(bucket, object, bucketDir, versionsObjectPath, versionsEntry, "updateLatestVersionAfterDeletion")
 			return nil
 		}