feat(ai): add raw API response logging at OpenAI client call sites

- Log the SDK response object immediately after client.chat.completions.create()
  in both generate() and readStreamingChatCompletion()
- These debug-level logs capture the response at the call site before any
  iteration or processing
- All downstream info-level logs continue to dump raw chunk/response objects

packages/ai/src/openai.ts

@@ -229,6 +229,8 @@ export class OpenAiApi extends AiApi {
         : {}),
     }, options.signal ? { signal: options.signal } : undefined);
 
+    this.log.debug("OpenAI API response", { response: JSON.parse(JSON.stringify(response)) });
+
     let accumulatedResponse = "";
     let accumulatedThinking = "";
     let usage: { promptTokens: number; completionTokens: number } | undefined;
@@ -466,6 +468,8 @@ export class OpenAiApi extends AiApi {
         : {}),
     }, signal ? { signal } : undefined);
 
+    this.log.debug("OpenAI API response", { response: JSON.parse(JSON.stringify(response)) });
+
     let content = "";
     let thinking = "";
     let chunkCount = 0;