feat(backend): implemented basic controller layer

7project/backend/app/schemas/category.py

@@ -0,0 +1,23 @@
+from typing import Optional
+from pydantic import BaseModel
+try:
+    # Pydantic v2
+    from pydantic import ConfigDict  # type: ignore
+    _HAS_V2 = True
+except Exception:  # pragma: no cover
+    _HAS_V2 = False
+
+class CategoryBase(BaseModel):
+    name: str
+    description: Optional[str] = None
+
+class CategoryCreate(CategoryBase):
+    pass
+
+class CategoryRead(CategoryBase):
+    id: int
+    if _HAS_V2:
+        model_config = ConfigDict(from_attributes=True)  # type: ignore
+    else:  # Pydantic v1 fallback
+        class Config:  # type: ignore
+            orm_mode = True