Trim and tighten code comments and docstrings across the repository. Comment-only: every changed file verified code-identical to main via AST/token comparison.
Raise ruff line-length to 100 and extend the local pre-commit format pipeline (def-signature magic-comma normalization, short multi-line assert collapse, kwarg '=' spacing, blank-line-after-short-import removal, adjacent string-literal / f-string+plain merge, redundant-pass pruning). Every transform re-checks the file AST and is dropped if it would differ; the whole-repo reformat is verified AST-identical per file and idempotent.
Adds studio/backend/utils/datasets/dataset_none_detect.py, a standalone scanner that reports None/empty content turns in alpaca, chatml, sharegpt, and gptoss datasets without modifying data, plus generator and runner scripts under tests/utils. Depends only on the datasets library and is not wired into the package init, so it stays import-light.
