feat: add per-channel HTTP transport controls

model/channel.go

@@ -954,6 +954,9 @@ func (channel *Channel) ValidateSettings() error {
 	if _, err := common.ParseProxyURLStrict(channelParams.Proxy); err != nil {
 		return fmt.Errorf("invalid channel proxy: %w", err)
 	}
+	if err := channelParams.ValidateHTTPTransport(); err != nil {
+		return err
+	}
 	channelOtherSettings := &dto.ChannelOtherSettings{}
 	if channel.OtherSettings != "" {
 		err := common.UnmarshalJsonStr(channel.OtherSettings, channelOtherSettings)

model/channel_settings_test.go

@@ -9,6 +9,38 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
+func TestChannelValidateSettingsRejectsInvalidHTTPTransport(t *testing.T) {
+	tests := []struct {
+		name    string
+		setting dto.ChannelSettings
+		wantErr string
+	}{
+		{
+			name:    "auto with shards is valid",
+			setting: dto.ChannelSettings{HTTPProtocol: "auto", HTTP2ConnectionShards: 4},
+		},
+		{
+			name:    "http1 with shards greater than one rejected",
+			setting: dto.ChannelSettings{HTTPProtocol: "http1", HTTP2ConnectionShards: 2},
+			wantErr: "http2_connection_shards",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			channel := &Channel{}
+			channel.SetSetting(tt.setting)
+			err := channel.ValidateSettings()
+			if tt.wantErr == "" {
+				require.NoError(t, err)
+				return
+			}
+			require.Error(t, err)
+			assert.Contains(t, err.Error(), tt.wantErr)
+		})
+	}
+}
+
 func TestAdvancedCustomChannelRequiresModelListRouteOnlyWhenUpdateChecksEnabled(t *testing.T) {
 	inferenceRoute := dto.AdvancedCustomRoute{
 		IncomingPath: "/v1/chat/completions",