Paper LaTeX sanitizer

Internal deterministic pre-publication sanitizer for meta-paper-write. It runs before the length, citation, and publication-quality gates.

The sanitizer performs only two bounded repairs:

• normalize U+2011, U+2013, and isolated U+2014 punctuation to LaTeX-safe ASCII equivalents while preserving paired Chinese em dashes (——);
• when EVIDENCE_STATUS: not_supplied, replace concrete forecast magnitudes in results-facing sections with TBD / 待实验确定. Planned setup values remain intact. A declared result threshold remains intact only when the same magnitude is present in the authoritative user request/paper contract; labeling an invented number as a target or hypothesis does not preserve it;
• remove only the known generated figure_placeholder_template or table_placeholder_template input line when the same manuscript already contains the corresponding inlined figure/table environment. Arbitrary user \input{...} commands and non-redundant template inputs remain untouched.