fix error in gitignore

apps/core/errors.py

@@ -0,0 +1,35 @@
+"""Consistent API error handling with stable error codes."""
+
+
+class ApiError(Exception):
+    """Raised by service/domain layers; converted to a consistent response."""
+
+    def __init__(self, code: str, message: str, details=None, status: int = 400):
+        self.code = code
+        self.message = message
+        self.details = details or {}
+        self.status = status
+        super().__init__(message)
+
+
+def error_response(code: str, message: str, details=None) -> dict:
+    return {"success": False, "error": {"code": code, "message": message, "details": details or {}}}
+
+
+def api_exception_handler(exc, context):
+    """DRF exception handler that emits the stable error envelope."""
+    from rest_framework.views import exception_handler
+    from rest_framework.response import Response
+
+    if isinstance(exc, ApiError):
+        return Response(error_response(exc.code, exc.message, exc.details), status=exc.status)
+
+    response = exception_handler(exc, context)
+    if response is not None:
+        if isinstance(response.data, dict) and "detail" in response.data and len(response.data) == 1:
+            return Response(
+                error_response("API_ERROR", str(response.data["detail"])),
+                status=response.status_code,
+            )
+        return Response(error_response("API_ERROR", "Request failed", {"errors": response.data}), status=response.status_code)
+    return None