pb: add address field to DataNodeInfo for proper node addressing

Previously, DataNodeInfo.Id was used as the node address, which worked
when Id was always ip:port. Now that Id can be an explicit string,
we need a separate Address field for connection purposes.

Changes:
- Add 'address' field to DataNodeInfo protobuf message
- Update ToDataNodeInfo() to populate the address field
- Update NewServerAddressFromDataNode() to use Address (with Id fallback)
- Fix LookupEcVolume to use dn.Url() instead of dn.Id()

Ref: https://github.com/seaweedfs/seaweedfs/issues/7487

weed/pb/master.proto

@@ -290,6 +290,7 @@ message DataNodeInfo {
   string id = 1;
   map<string, DiskInfo> diskInfos = 2;
   uint32 grpc_port = 3;
+  string address = 4; // ip:port for connecting to the volume server
 }
 message RackInfo {
   string id = 1;

weed/pb/master_pb/master.pb.go

@@ -2047,6 +2047,7 @@ type DataNodeInfo struct {
 	Id            string                 `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
 	DiskInfos     map[string]*DiskInfo   `protobuf:"bytes,2,rep,name=diskInfos,proto3" json:"diskInfos,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"bytes,2,opt,name=value"`
 	GrpcPort      uint32                 `protobuf:"varint,3,opt,name=grpc_port,json=grpcPort,proto3" json:"grpc_port,omitempty"`
+	Address       string                 `protobuf:"bytes,4,opt,name=address,proto3" json:"address,omitempty"` // ip:port for connecting to the volume server
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -2102,6 +2103,13 @@ func (x *DataNodeInfo) GetGrpcPort() uint32 {
 	return 0
 }
 
+func (x *DataNodeInfo) GetAddress() string {
+	if x != nil {
+		return x.Address
+	}
+	return ""
+}
+
 type RackInfo struct {
 	state         protoimpl.MessageState `protogen:"open.v1"`
 	Id            string                 `protobuf:"bytes,1,opt,name=id,proto3" json:"id,omitempty"`
@@ -4263,11 +4271,12 @@ const file_master_proto_rawDesc = "" +
 	"\fvolume_infos\x18\x06 \x03(\v2#.master_pb.VolumeInformationMessageR\vvolumeInfos\x12P\n" +
 	"\x0eec_shard_infos\x18\a \x03(\v2*.master_pb.VolumeEcShardInformationMessageR\fecShardInfos\x12.\n" +
 	"\x13remote_volume_count\x18\b \x01(\x03R\x11remoteVolumeCount\x12\x17\n" +
-	"\adisk_id\x18\t \x01(\rR\x06diskId\"\xd4\x01\n" +
+	"\adisk_id\x18\t \x01(\rR\x06diskId\"\xee\x01\n" +
 	"\fDataNodeInfo\x12\x0e\n" +
 	"\x02id\x18\x01 \x01(\tR\x02id\x12D\n" +
 	"\tdiskInfos\x18\x02 \x03(\v2&.master_pb.DataNodeInfo.DiskInfosEntryR\tdiskInfos\x12\x1b\n" +
-	"\tgrpc_port\x18\x03 \x01(\rR\bgrpcPort\x1aQ\n" +
+	"\tgrpc_port\x18\x03 \x01(\rR\bgrpcPort\x12\x18\n" +
+	"\aaddress\x18\x04 \x01(\tR\aaddress\x1aQ\n" +
 	"\x0eDiskInfosEntry\x12\x10\n" +
 	"\x03key\x18\x01 \x01(\tR\x03key\x12)\n" +
 	"\x05value\x18\x02 \x01(\v2\x13.master_pb.DiskInfoR\x05value:\x028\x01\"\xf0\x01\n" +

weed/pb/server_address.go

@@ -2,11 +2,12 @@ package pb
 
 import (
 	"fmt"
-	"github.com/seaweedfs/seaweedfs/weed/pb/master_pb"
-	"github.com/seaweedfs/seaweedfs/weed/util"
 	"net"
 	"strconv"
 	"strings"
+
+	"github.com/seaweedfs/seaweedfs/weed/pb/master_pb"
+	"github.com/seaweedfs/seaweedfs/weed/util"
 )
 
 type ServerAddress string
@@ -32,7 +33,12 @@ func NewServerAddressWithGrpcPort(address string, grpcPort int) ServerAddress {
 }
 
 func NewServerAddressFromDataNode(dn *master_pb.DataNodeInfo) ServerAddress {
-	return NewServerAddressWithGrpcPort(dn.Id, int(dn.GrpcPort))
+	// Use Address field if available (new behavior), fall back to Id for backward compatibility
+	addr := dn.Address
+	if addr == "" {
+		addr = dn.Id // backward compatibility: old nodes use ip:port as id
+	}
+	return NewServerAddressWithGrpcPort(addr, int(dn.GrpcPort))
 }
 
 func NewServerAddressFromLocation(dn *master_pb.Location) ServerAddress {

weed/server/master_grpc_server_volume.go

@@ -253,7 +253,7 @@ func (ms *MasterServer) LookupEcVolume(ctx context.Context, req *master_pb.Looku
 		var locations []*master_pb.Location
 		for _, dn := range shardLocations {
 			locations = append(locations, &master_pb.Location{
-				Url:        string(dn.Id()),
+				Url:        dn.Url(),
 				PublicUrl:  dn.PublicUrl,
 				DataCenter: dn.GetDataCenterId(),
 			})

weed/topology/data_node.go

@@ -269,6 +269,7 @@ func (dn *DataNode) ToDataNodeInfo() *master_pb.DataNodeInfo {
 		Id:        string(dn.Id()),
 		DiskInfos: make(map[string]*master_pb.DiskInfo),
 		GrpcPort:  uint32(dn.GrpcPort),
+		Address:   dn.Url(), // ip:port for connecting to the volume server
 	}
 	for _, c := range dn.Children() {
 		disk := c.(*Disk)