feat（新功能）: brand name slogan logo 生成服务

fix（修复bug）:
docs（文档变更）:
refactor（重构）:
test(增加测试):

app/schemas/brand_dna.py

@@ -4,3 +4,8 @@ from pydantic import BaseModel
 class BrandDnaModel(BaseModel):
     image_url: str
     is_brand_dna: bool
+
+
+class GenerateBrandModel(BaseModel):
+    user_id: str
+    prompt: str