[Dev] Add LlamaIndex Vector Index Adapter

[ohdearquant]

Description

Implement an adapter for LlamaIndex Vector Index to integrate with LionAGI's memory system.

Objectives

1. Create LlamaIndexVectorIndexAdapter class to interface with LlamaIndex's vector index functionality
2. Enable seamless integration between LionAGI's memory items and LlamaIndex's vector storage
3. Support efficient vector search and retrieval
4. Maintain consistency with LionAGI's memory interface

Technical Requirements

• Support all vector index types from LlamaIndex
• Implement vector similarity search
• Handle batch operations efficiently
• Preserve metadata during index operations
• Support customizable embedding functions

Implementation Tasks

• Create adapter class structure
• Implement index creation and management
• Add vector search capabilities
• Implement batch operations
• Add metadata handling
• Write comprehensive tests
• Create documentation

Core Features

1. Vector Index Operations:

   • Creation and initialization
   • Adding/removing vectors
   • Updating existing entries
   • Batch operations

2. Search Capabilities:

   • Similarity search
   • K-nearest neighbors
   • Filtered search
   • Hybrid search (combining vector and metadata)

3. Integration Features:

   • Custom embedding support
   • Metadata preservation
   • Bulk operations
   • Performance optimization

Testing Requirements

• Unit tests for all operations
• Integration tests with LionAGI memory system
• Performance benchmarks
• Edge case handling
• Concurrent operation testing

Documentation Requirements

• API documentation
• Usage examples
• Performance guidelines
• Integration guide
• Best practices

Dependencies

• LlamaIndex
• Vector store backends
• LionAGI core packages