fix: add message attribute to BrainusError for improved exception handling

Author: 0xneobyte

CHANGELOG.md

@@ -10,6 +10,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
 
 - Fixed API key validation to raise `AuthenticationError` instead of `ValueError` for invalid format, ensuring consistent error handling
+- Added `message` attribute to all Brainus AI exceptions to support `e.message` access pattern
 
 ## [0.1.5] - 2025-12-12
 

src/brainus_ai/exceptions.py

@@ -4,7 +4,9 @@
 class BrainusError(Exception):
     """Base exception for all Brainus AI errors."""
 
-    pass
+    def __init__(self, message: str, *args: object) -> None:
+        super().__init__(message, *args)
+        self.message = message
 
 
 class AuthenticationError(BrainusError):