feat: organize lists with drag and drop

backend/schemas.py

@@ -74,8 +74,30 @@ class ListOut(BaseModel):
     folder_id: UUID | None
     name: str
     is_inbox: bool
+    position: int
 
 
+class ListMove(BaseModel):
+    folder_id: UUID | None
+    list_ids: list[UUID] = Field(min_length=1)
+
+    @model_validator(mode="after")
+    def unique_ids(self):
+        if len(self.list_ids) != len(set(self.list_ids)):
+            raise ValueError("list_ids must be unique")
+        return self
+
+
+class ListReorder(BaseModel):
+    folder_id: UUID | None
+    list_ids: list[UUID] = Field(min_length=1)
+
+    @model_validator(mode="after")
+    def unique_ids(self):
+        if len(self.list_ids) != len(set(self.list_ids)):
+            raise ValueError("list_ids must be unique")
+        return self
+
 
 class TaskCreate(BaseModel):
     title: str = Field(min_length=1, max_length=500)