fix(channel): 修复前台自定义渠道模型配置抽屉空白死锁，并在启动时保护管理员能力配置 (#360)

Co-authored-by: Danborad <danborad@github.com>

backend/internal/service/model_capability.go

@@ -68,6 +68,7 @@ type ParameterSupport struct {
 type VideoCapabilityConfig struct {
 	References        VideoReferenceConfig `json:"references"`
 	Duration          VideoDurationConfig  `json:"duration"`
+	DurationSupported *bool                `json:"durationSupported,omitempty"`
 	Ratios            []string             `json:"ratios"`
 	DefaultRatio      string               `json:"defaultRatio"`
 	Resolutions       []string             `json:"resolutions"`
@@ -109,6 +110,10 @@ func DefaultModelCapabilityConfig(protocol string) *ModelCapabilityConfig {
 	return DefaultModelCapabilityConfigForModel(protocol, "")
 }
 
+func videoDurationSupported(value *VideoCapabilityConfig) bool {
+	return value == nil || value.DurationSupported == nil || *value.DurationSupported
+}
+
 func DefaultImageCapabilityConfig(protocol string, modelName string) *ImageCapabilityConfig {
 	image := &ImageCapabilityConfig{
 		References:            ImageReferenceConfig{PromptMaxChars: 32000, MaxImages: 16, MaxImageBytes: 30 * 1024 * 1024, MaskSupported: true},