feat: enhance request handling with pass-through options and system prompt support

dto/channel_settings.go

@@ -1,7 +1,9 @@
 package dto
 
 type ChannelSettings struct {
-	ForceFormat       bool   `json:"force_format,omitempty"`
-	ThinkingToContent bool   `json:"thinking_to_content,omitempty"`
-	Proxy             string `json:"proxy"`
+	ForceFormat            bool   `json:"force_format,omitempty"`
+	ThinkingToContent      bool   `json:"thinking_to_content,omitempty"`
+	Proxy                  string `json:"proxy"`
+	PassThroughBodyEnabled bool   `json:"pass_through_body_enabled,omitempty"`
+	SystemPrompt           string `json:"system_prompt,omitempty"`
 }