feat: new file

backend/app/routes/ai.py

@@ -0,0 +1,24 @@
+from __future__ import annotations
+
+from fastapi import APIRouter
+from pydantic import BaseModel, Field
+
+from ..services.ai_insight import generate_insight
+
+
+router = APIRouter()
+
+
+class InsightRequest(BaseModel):
+    query: str = Field(..., min_length=1, max_length=2000)
+    product_id: str | None = None
+    top_k: int = Field(6, ge=1, le=20)
+
+
+@router.post("/insight")
+def insight(req: InsightRequest):
+    """
+    基于向量检索 + LLM（可选）输出“爆款发现 -> 数据验证 -> 决策跟卖”的建议。
+    """
+    return generate_insight(query=req.query, product_id=req.product_id, top_k=req.top_k)
+