Remove default concurrent upload/download limits for best performance (#7712)

Change all concurrentUploadLimitMB and concurrentDownloadLimitMB defaults
from fixed values (64, 128, 256 MB) to 0 (unlimited).

This removes artificial throttling that can limit throughput on high-performance
systems, especially on all-flash setups with many cores.

Files changed:
- volume.go: concurrentUploadLimitMB 256->0, concurrentDownloadLimitMB 256->0
- server.go: filer/volume/s3 concurrent limits 64/128->0
- s3.go: concurrentUploadLimitMB 128->0
- filer.go: concurrentUploadLimitMB 128->0, s3.concurrentUploadLimitMB 128->0

Users can still set explicit limits if needed for resource management.

1 files changed, 1 insertions, 1 deletions

diff --git a/weed/command/s3.go b/weed/command/s3.go
index 5fb34155b..5f62e8e58 100644
--- a/weed/command/s3.go
+++ b/weed/command/s3.go
@@ -84,7 +84,7 @@ func init() {
 	s3StandaloneOptions.localFilerSocket = cmdS3.Flag.String("localFilerSocket", "", "local filer socket path")
 	s3StandaloneOptions.localSocket = cmdS3.Flag.String("localSocket", "", "default to /tmp/seaweedfs-s3-<port>.sock")
 	s3StandaloneOptions.idleTimeout = cmdS3.Flag.Int("idleTimeout", 120, "connection idle seconds")
-	s3StandaloneOptions.concurrentUploadLimitMB = cmdS3.Flag.Int("concurrentUploadLimitMB", 128, "limit total concurrent upload size")
+	s3StandaloneOptions.concurrentUploadLimitMB = cmdS3.Flag.Int("concurrentUploadLimitMB", 0, "limit total concurrent upload size, 0 means unlimited")
 	s3StandaloneOptions.concurrentFileUploadLimit = cmdS3.Flag.Int("concurrentFileUploadLimit", 0, "limit number of concurrent file uploads, 0 means unlimited")
 }