Complete Task 1.3 - Authentication System Implementation

✅ Implemented comprehensive authentication system:
- Abstract AuthHandler base class with pluggable architecture
- APIKeyAuth for API key authentication (string auto-conversion)
- JWTAuth for JWT token authentication with expiration handling
- NoAuth for testing and public instances
- Full integration with WikiJSClient for automatic header management

🔧 Fixed packaging issues:
- Updated pyproject.toml with required project metadata fields
- Fixed utility function exports in utils/__init__.py
- Package now installs correctly in virtual environments

🧪 Validated with comprehensive tests:
- All authentication methods working correctly
- Proper error handling for invalid credentials
- Type validation and security features

📊 Progress: Phase 1 MVP Development now 60% complete
🎯 Next: Task 1.4 - Pages API implementation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

wikijs/auth/__init__.py

@@ -1,19 +1,21 @@
 """Authentication module for wikijs-python-sdk.
 
-This module will contain authentication handlers for different
+This module contains authentication handlers for different
 authentication methods supported by Wiki.js.
 
-Future implementations:
-- API key authentication
-- JWT token authentication  
-- OAuth2 authentication
+Supported authentication methods:
+- API key authentication (APIKeyAuth)
+- JWT token authentication (JWTAuth)
+- No authentication for testing (NoAuth)
 """
 
-# Placeholder for future authentication implementations
-# from .base import AuthHandler
-# from .api_key import APIKeyAuth
-# from .jwt import JWTAuth
+from .base import AuthHandler, NoAuth
+from .api_key import APIKeyAuth
+from .jwt import JWTAuth
 
 __all__ = [
-    # Will be implemented in Task 1.3
+    "AuthHandler",
+    "NoAuth", 
+    "APIKeyAuth",
+    "JWTAuth",
 ]