v2.1

New Features:

1. Observability with Langfuse
   • Integrated Langfuse tracing to track LLM calls, tool usage, and graph execution across the full pipeline.
   • Added dedicated observability.ipynb notebook with a step-by-step guide to set up and use Langfuse with the system.

2. Streaming Response & Agent Transparency
   • Responses now stream token by token directly in the Gradio interface.
   • Agent reasoning is now visible in real time: tool calls (search_child_chunks, retrieve_parent_chunks) and their results are shown as collapsible messages during execution.
   • System nodes (query rewriting, history summarization) surface their output progressively, including clarification requests when the query is unclear.

Bug Fixes:

1. Docker Volume Permission Fix
   • Fixed a PermissionError when clicking "Clear All" with Docker-mounted volumes.
   • Directories are now cleared by removing their contents instead of deleting the root folder, avoiding permission issues with mount points.