feat: wire TradingGraph to use settings for model, temperature, and risk config

app/lib/openrouter.ts

@@ -36,7 +36,8 @@ export class OpenRouterClient {
 
   async createChatCompletion(
     messages: Message[],
-    model?: string
+    model?: string,
+    options?: { temperature?: number; max_tokens?: number }
   ): Promise<unknown> {
     const response = await fetch(`${this.baseURL}/chat/completions`, {
       method: "POST",
@@ -49,6 +50,8 @@ export class OpenRouterClient {
       body: JSON.stringify({
         model: model ?? this.defaultModel,
         messages,
+        ...(options?.temperature != null && { temperature: options.temperature }),
+        ...(options?.max_tokens != null && { max_tokens: options.max_tokens }),
       }),
     });