fix: eliminate yfinance rate limiting - retry backoff in cached helper + Celery tasks use cached helper instead of raw yf.Ticker every 2min

fix: resolve Celery decorator syntax error and handle NaN technical indicators in ONNX prediction inputs

feat: implement weekly MLOps retraining loop and specialized multi-model router

fix: resolve Celery asyncpg event loop crash with NullPool and guard PnL division by zero

feat: add user strategy performance tracker table, lockInStrategy GraphQL mutation, and auto-labeler updates

feat: add MLOps prediction logs table, background labeling task, and model metrics endpoint

feat: add secure 6-digit OTP email verification flow

feat: implement real-time price alerts via email with 2-minute reminder loops

feat: implement Celery task queue and background tasks for watchlist reports and database pruning

feat: changes into the tech stack