fix: rename avaliable_tools to available_tools with backward compatibility

[tdan1]

• Fixed typo in field name across CustomAgent and SpoonReactAI classes

🐛 Fix: Rename avaliable_tools to available_tools

Problem
The field avaliable_tools was misspelled throughout the codebase, causing API inconsistency and potential developer confusion.

Solution

• ✅ Renamed avaliable_tools to available_tools in affected classes
• ✅ Added backward compatibility with deprecation warnings
• ✅ Updated all internal references
• ✅ Added comprehensive test coverage

Changes Made

• spoon_ai/agents/custom_agent.py: Fixed field name and added compatibility property
• spoon_ai/agents/spoon_react.py: Fixed field name and added compatibility property
• tests/test_typo_fix.py: Added test coverage for fix and backward compatibility
• CHANGELOG.md: Documented the change and deprecation

Testing

• ✅ All existing tests pass
• ✅ New tests added with 100% coverage of changed code
• ✅ Manual testing confirms no breaking changes
• ✅ Backward compatibility tested with deprecation warnings

Backward Compatibility

Existing code using avaliable_tools will continue to work but will receive deprecation warnings. Migration path:

# Old code (still works, shows warning):
agent.avaliable_tools.add_tool(my_tool)

# New code (recommended):
agent.available_tools.add_tool(my_tool)

 backward compatibility with deprecation warnings

@property
    def avaliable_tools(self):
        """Backward compatibility property for misspelled field name."""
        import warnings
        warnings.warn(
            "avaliable_tools is deprecated and will be removed in v2.0. "
            "Use available_tools instead.",
            DeprecationWarning,
            stacklevel=2
        )
        return self.available_tools

@avaliable_tools.setter
def avaliable_tools(self, value):
    """Backward compatibility setter for misspelled field name."""
    import warnings
    warnings.warn(
        "avaliable_tools is deprecated and will be removed in v2.0. "
        "Use available_tools instead.",
        DeprecationWarning,
        stacklevel=2
    )
    self.available_tools = value