Restore typed http2.StreamError check; add x/net license metadata

The previous fixup dropped the typed errors.As(err, &http2.StreamError{})
check because importing golang.org/x/net/http2 promoted golang.org/x/net
from indirect to direct in go.mod and tripped the SPDX license test.

Per CLAUDE.md, we should not branch on err.Error() content when a typed
sentinel is available, so restore the typed check and pay the license
metadata tax instead:
- Add // BSD-3-Clause suffix on the direct require in go.mod.
- Add a matching entry to NOTICE under the BSD (3-clause) section.

Update the test that previously claimed to cover the wrapped/typed form
(but actually used errors.New) to wrap a real http2.StreamError.

Co-authored-by: Isaac

Author: anton-107

NOTICE

@@ -103,6 +103,10 @@ golang.org/x/mod - https://github.com/golang/mod
 Copyright 2009 The Go Authors.
 License - https://github.com/golang/mod/blob/master/LICENSE
 
+golang.org/x/net - https://github.com/golang/net
+Copyright 2009 The Go Authors.
+License - https://github.com/golang/net/blob/master/LICENSE
+
 golang.org/x/oauth2 - https://github.com/golang/oauth2
 Copyright 2009 The Go Authors.
 License - https://github.com/golang/oauth2/blob/master/LICENSE

experimental/ssh/internal/client/releases.go

@@ -15,6 +15,7 @@ import (
 	"github.com/databricks/cli/libs/filer"
 	"github.com/databricks/cli/libs/log"
 	"github.com/databricks/databricks-sdk-go"
+	"golang.org/x/net/http2"
 )
 
 type releaseProvider func(ctx context.Context, architecture, version, releasesDir string) (io.ReadCloser, error)
@@ -83,9 +84,14 @@ func uploadReleases(ctx context.Context, workspaceFiler filer.Filer, getRelease
 
 // isStreamResetError reports whether err looks like an HTTP/2 stream reset from
 // the server, which typically means an edge proxy or the workspace-files import
-// endpoint rejected the request body (e.g. body-size limit). Matches both the
-// raw http2.StreamError.Error() format and wrapped variants.
+// endpoint rejected the request body (e.g. body-size limit). The string fallback
+// catches cases where a transport layer re-formats the http2 error before it
+// reaches us, losing the typed value but preserving the message shape.
 func isStreamResetError(err error) bool {
+	var se http2.StreamError
+	if errors.As(err, &se) {
+		return true
+	}
 	msg := err.Error()
 	return strings.Contains(msg, "stream error") && strings.Contains(msg, "stream ID")
 }

experimental/ssh/internal/client/releases_test.go

@@ -6,6 +6,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"golang.org/x/net/http2"
 )
 
 func TestIsStreamResetError(t *testing.T) {
@@ -15,13 +16,13 @@ func TestIsStreamResetError(t *testing.T) {
 		want bool
 	}{
 		{
-			name: "raw http2 stream error string",
-			err:  errors.New("stream error: stream ID 15; NO_ERROR"),
+			name: "typed http2.StreamError wrapped",
+			err:  fmt.Errorf(`Post "https://example/api/2.0/workspace-files/import-file/...": %w`, http2.StreamError{StreamID: 15, Code: http2.ErrCodeNo}),
 			want: true,
 		},
 		{
-			name: "wrapped peer-reset error (Go HTTP/2 client format)",
-			err:  fmt.Errorf(`Post "https://example/api/2.0/workspace-files/import-file/...": %w`, errors.New("stream error: stream ID 15; NO_ERROR; received from peer")),
+			name: "stringified stream error",
+			err:  errors.New("stream error: stream ID 15; NO_ERROR; received from peer"),
 			want: true,
 		},
 		{

go.mod

@@ -37,6 +37,7 @@ require (
 	go.yaml.in/yaml/v3 v3.0.4 // MIT AND Apache-2.0
 	golang.org/x/crypto v0.49.0 // BSD-3-Clause
 	golang.org/x/mod v0.34.0 // BSD-3-Clause
+	golang.org/x/net v0.51.0 // BSD-3-Clause
 	golang.org/x/oauth2 v0.36.0 // BSD-3-Clause
 	golang.org/x/sync v0.20.0 // BSD-3-Clause
 	golang.org/x/sys v0.43.0 // BSD-3-Clause
@@ -97,7 +98,6 @@ require (
 	go.opentelemetry.io/otel/metric v1.43.0 // indirect
 	go.opentelemetry.io/otel/trace v1.43.0 // indirect
 	golang.org/x/exp v0.0.0-20240222234643-814bf88cf225 // indirect
-	golang.org/x/net v0.51.0 // indirect
 	golang.org/x/time v0.14.0 // indirect
 	google.golang.org/api v0.265.0 // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260203192932-546029d2fa20 // indirect