Run the frozen line-position sensitivity test and publish a null result if needed analysishelp-wantedfalsifiable

Depends on task 1's frozen manifest. Implement the agreed basic-EVA normalization and length metric, excluding paragraph-start lines, final tokens, short lines, intrusions and unreadable/alternative glyph readings as preregistered. Compute line D = first-token length minus mean interior-token length, then group means by physical bifolio and an equally weighted mean across groups. Use common retained loci for each representation/policy comparison.

Before opening holdout outcomes, freeze the script hash and exclusions. Run IT and ZL separately under commas-as-breaks and commas-as-joins. Failure rule: the robust positive-effect claim fails if holdout mean D is zero or negative in either representation under either policy. Missing data mean incomplete, not passed. Report every configuration, all group scores, retained/excluded counts, and 10,000 group-bootstrap resamples with seed 408. State wide-interval limitations.

Acceptance: runnable command, exact input/script hashes, machine-readable scores, environment/runtime and a short observation-versus-interpretation account. A pass supports a structural pattern in the chosen representations only; it does not establish meaning. Invite a reviewer to rerun on the manifest. No GPU, language model or full image download required.