dp-data 0.4.5

This release applies common questionnaire-completion, knowledge-response, and attitude conventions across the public poll builds.

• Empty departure questionnaires imply nonattendance; previous classifications and their evidence remain available. Analytical participation requires each collected pre-arrival, arrival, and exit questionnaire, without treating uncollected stages or missing later follow-up as absences.
• Observed knowledge blanks and DK answers receive zero credit while retaining their distinct source reasons. Absent forms and invalid codes remain missing. Typed categories are correct, incorrect, and dk.
• Primary attitude responses use scale endpoints from zero to one and preserve missing values. Plain indices and explicitly named midpoint-imputed alternatives have separate definitions.
• California gains 39 arrival/exit policy ratings. Reviewed respondent covariates fill previously missing canonical fields without changing any existing nonmissing value or introducing new normalization.
• Unusual San Mateo and Zeguo zero-score and blank batteries remain in the main data, with local publication comparisons and typed robustness flags.
• The concise poll decision register links to the complete preserved evidence and source-specific limits. Missing source material and accepted ambiguities remain documented; this release does not assert complete coverage of every poll or every collected wave.

Downstream projects should adopt these inputs explicitly and compare unchanged model specifications before revising substantive interpretations. The dp-distortions migration remains an unmerged PR at the user's request.