[Integration] LlamaIndex Custom LLM Adapter

[ishangupta-ds]

Overview

Provide native TuringEngine LLM class for run-llama/llama_index for fast RAG indexing.

Key Deliverables

• Submit PR to LlamaIndex community hub for llama-index-llms-turing.
• Validate vector store retrieval with streaming generation.
• Publish standalone PyPI package wrapper.

Upstream Reference

See integrations/llamaindex/UPSTREAM_PR.md.

[ishangupta-ds]

🚀 Upstream Pull Request submitted to run-llama/llama_index: run-llama/llama_index#22830