feat(P3): 5개 서비스 비즈니스 이벤트 logger.info 보강

stock/app/main.py

@@ -256,6 +256,7 @@ def order_stock(req: OrderRequest):
         if resp.status_code != 200:
             logger.error(f"Order Error: {resp.status_code}")
             return JSONResponse(status_code=resp.status_code, content=resp.json())
+        logger.info(f"Order Response: {req.action} {req.ticker} x{req.quantity} → OK")
         return resp.json()
     except ValueError:
         status = resp.status_code if resp is not None else 502
@@ -279,6 +280,7 @@ def ai_coach(req: AiCoachRequest):
 
     allowed_models = {"claude-haiku-4-5-20251001", "claude-sonnet-4-6"}
     model = req.model if req.model in allowed_models else "claude-haiku-4-5-20251001"
+    logger.info(f"AI Coach 호출: model={model}, prompt_len={len(req.prompt)}")
 
     try:
         resp = requests.post(
@@ -298,7 +300,10 @@ def ai_coach(req: AiCoachRequest):
         if resp.status_code != 200:
             logger.error(f"Anthropic API error: {resp.status_code}")
             return JSONResponse(status_code=resp.status_code, content={"error": "AI API error"})
-        return resp.json()
+        data = resp.json()
+        usage = data.get("usage", {})
+        logger.info(f"AI Coach 응답 완료: model={model}, input={usage.get('input_tokens', '?')}, output={usage.get('output_tokens', '?')}")
+        return data
     except requests.Timeout:
         return JSONResponse(status_code=504, content={"error": "AI API timeout"})
     except Exception as e: