[ctoth]

Five implementations still encoded contracts contradicted by the original paper page images reviewed for #108. This series corrects each implementation in its own commit and updates the existing tests and documentation that asserted the same incorrect behavior.

• 6a2a33a: revised impact removes external attacks entering the influencing set; target-preserving deletion removes edges incident to every member of that set. The existing self-attack example now expects negative impact.
• d308240: PAF distance charges 0.5 for ignorance versus a definite relation and 1 for attack versus non-attack, including float objective annotations.
• 152277f: consensual expansion imports the full profile's uncontested relations while preserving the source's commitments. API change: consensual_expansion now takes the profile as its second argument; repository callers and docs are updated.
• 4682283: AF change classification uses the paper's extension-family cardinalities and quantifiers, including decisive precedence and the equal-count requirement for expansive changes.
• c56d764: transposition closure retains seed rules and generated transpositions, including contradictory antecedents and conclusions already among the antecedents. Unsupported pruning and the corresponding false test invariant are removed.

Evidence: original page images only, for AlAnaissy 2024 pp. 1, 3–4; Coste-Marquis 2007 pp. 6–10; Cayrol et al. (2010 publication in the local 2014 directory) pp. 6, 8–11; and Prakken 2010 p. 12. No PDF text extraction or OCR was used.

Existing assertions and generators are corrected; no new test functions or guards are added. The argument builder's existing restriction to non-repeating conclusion paths remains a limitation outside this series; the existing nontriviality property now states that restriction explicitly.

Validation runs in this PR's existing Python 3.11/3.14 workflow. No local CI steps were run. This PR is left open for review.