feat(project): 项目编号支持新增编辑自由填写

项目管理弹窗增加项目编号输入；后端保存改为接收客户端编号并校验租户内唯一，不再自动生成。

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/app/api/project_management.py

@@ -45,6 +45,7 @@ class TeamBody(Body):
 
 class ProjectBody(Body):
     projectName: str = Field(min_length=1, max_length=200)
+    projectNo: str = Field(min_length=1, max_length=64)
     teamId: str
     leaderUserId: str
     bizTypes: List[str]