feat: default ingest to Yahoo and restore a full README

Add multi-asset portfolio support with a cross-sectional null

Fix three correctness bugs in the Yahoo ingest

Add algotrader 2.0: a backtester that tries to prove itself wrong

feat: add Yahoo ingest on the FinRL tree and stop extra branch creation

feat(ui): add robust multi-interface UI system (Streamlit, Dash, Jupyter, WebSocket) with launcher, docs, and integration tests [skip ci]

feat: comprehensive test suite fixes and improvements

Fix all test issues and improve system stability

Fix OpenCV import for RL tests, mark slow RL tests, and document in README

Add FinRL integration with comprehensive RL trading agent

Initial commit: Enhanced Algorithmic Trading System with Synthetic Data Generation, Comprehensive Logging, and Extensive Testing