v1.2: the census language pass

The census language pass. The method page has said since first publication
that record-checked attributes are tested over the complete population; the
texts now say it too.

• Attribute texts read "for each X" / "for all X"; period-form pass criteria
  read "every X in the period"; collection playbooks ask for the population,
  not a sample of it. The exception rule is unchanged: an isolated miss in an
  otherwise working practice is an exception, not a gap, and the published
  deviation rule decides systematic.
• Every record-checked attribute carries a frequency field, the input to
  the published fallback-selection table for the rare population where a
  complete pull is impracticable. Attributes drawing on the same population
  carry the same frequency.
• The readiness verdict vocabulary gains absent (the practice itself does
  not exist), distinct from gap (the practice exists but cannot be
  evidenced). Recording an absence requires the operator's own words.
• Deliberate survivor: DAT-04's "sampled data," which means data-subsetting
  for non-production environments, not audit sampling. Machine identifiers
  (the sample attribute type, sample_eligible) keep their names.