feat: enhance OpenRouter enterprise support with new settings and response handling

relay/channel/openrouter/dto.go

@@ -1,5 +1,7 @@
 package openrouter
 
+import "encoding/json"
+
 type RequestReasoning struct {
 	// One of the following (not both):
 	Effort    string `json:"effort,omitempty"`     // Can be "high", "medium", or "low" (OpenAI-style)
@@ -7,3 +9,8 @@ type RequestReasoning struct {
 	// Optional: Default is false. All models support this.
 	Exclude bool `json:"exclude,omitempty"` // Set to true to exclude reasoning tokens from response
 }
+
+type OpenRouterEnterpriseResponse struct {
+	Data    json.RawMessage `json:"data"`
+	Success bool            `json:"success"`
+}