Add unified interface for echo9ml.py - implement module-level create_deep_tree_echo function

[Copilot]

This PR addresses the fragment analysis for echo9ml.py by implementing a unified interface that standardizes the API for integration with other Deep Tree Echo components.

Problem

The fragment analysis identified that echo9ml.py was missing a module-level create_deep_tree_echo function, which was preventing proper integration with the unified Deep Tree Echo architecture. The function existed only as a class method PersonaKernel.create_deep_tree_echo(), breaking API consistency with other Echo components.

Solution

Added a module-level create_deep_tree_echo() function that provides a unified factory interface:

def create_deep_tree_echo() -> PersonaKernel:
    """Create a Deep Tree Echo persona kernel
    
    Module-level convenience function for creating the default Deep Tree Echo
    persona kernel. Provides unified API for integration with other components.
    
    Returns:
        PersonaKernel: Initialized Deep Tree Echo persona kernel
    """
    return PersonaKernel.create_deep_tree_echo()

Changes Made

1. Added module-level factory function - create_deep_tree_echo() now available at module level for consistent API
2. Updated exports - Added the new function to __all__ list for proper module interface
3. Enhanced test coverage - Extended test_echo9ml.py with tests validating the new function works identically to the class method
4. Updated documentation - Enhanced ECHO9ML_README.md with new API usage examples and updated DEEP_TREE_ECHO_CATALOG.md to reflect completion status

Integration Benefits

• API Consistency: Now matches the factory function pattern used across other Echo components (like create_deep_tree_echo_analyzer())
• Simplified Imports: Enables clean imports like from echo9ml import create_deep_tree_echo, create_echo9ml_system
• Backward Compatibility: Existing code using PersonaKernel.create_deep_tree_echo() continues to work unchanged
• Integration Ready: Ready for use with unified launcher and cognitive architecture integration

Usage

# New unified API
from echo9ml import create_deep_tree_echo, create_echo9ml_system

# Create persona kernel directly
persona = create_deep_tree_echo()

# Or create complete system
system = create_echo9ml_system()

The echo9ml.py fragment is now properly integrated with the unified Deep Tree Echo architecture and ready for the next phase of cognitive system consolidation.

Fixes #19.

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.