Apply changes from PR #393 by @MarcoGorworworelli:
- Normalize covariates per-input instead of batch-wide to prevent
each input's result from depending on batch composition
- Fit separate ridge regressions per time series instead of a single
batched regression, preventing cross-series data leakage
- Applied to both src/timesfm/utils/xreg_lib.py and v1/src/timesfm/xreg_lib.py
darkpowerxo
a63360a57c