feat(ddi): skip logic and validation in the codebook (#151)

[jstet]

Closes #151. Part 1 of the round-trip plan, #155.

DDI Codebook 2.5 has no expression syntax, so each condition goes in twice (convention:logicMapping, new ddiEncoding):

• Readable, in standard elements:
  • <universe clusion="I"> prose, built from the expression and the labels it refers to.
  • A simple numeric range (. >= 1 and . <= 10, . > 0) on an integer or decimal is also written as <valrng><range min/max/minExclusive/maxExclusive>.
• Exact, in typed notes (the XSD's controlled-vocabulary extension point), written last in var and varGrp:
  • cdl:relevant and cdl:constraint, both with subject="xlsform-xpath".
  • cdl:constraint_message, one per xml:lang.
  • cdl:required.

<universe clusion="I">Nur wenn „Haben Sie einen Hund?“ = Ja</universe>
<universe clusion="I" xml:lang="en">Only if “Do you have a dog?” = Yes</universe>
…
<notes type="cdl:relevant" subject="xlsform-xpath">${hund} = 'ja'</notes>

The 8 agreed corrections

1. Plain groups: their conditions are ANDed into each variable's own until DDI round trips: keep question order, every group, and notes apart from hints #152 gives them a varGrp.
2. ${name} resolves to a var or a varGrp name. A select_multiple's logic sits on its varGrp type="multipleResp", and the semi-open multi's on its varGrp type="other". Each binary var also gets the universe prose, for readers.
3. Element order follows the XSD: qstn, then valrng, then universe, then catgry, concept, varFormat, and notes last.
4. Schematron: any number of typed notes, and at most one untyped note per language.
5. LimeSurvey input: lstsv2ddi reverses relevance and constraints (expressions: true). An EM expression outside the dialect gets an em-unsupported warning and no note; the conversion no longer fails on it. lstsvToDdiXml gains onWarning, and the API and CLI pass it through.
6. Prose templates are registry data, English and German only for now.
   • Covered: =, !=, comparisons, selected(), and, or, not(), and comparing with '' (answered / not answered).
   • Anything else gets no universe, but the note still carries the expression.
   • A language gets no universe if any label it needs is missing in that language. No text is filled in from another language.
   • An untagged codebook uses English.
7. cdl:required is written only for required questions, with the text yes.
8. valrng is added as described above.

Also

• "Other" text box: the synthesized companion of or_other or LimeSurvey's other=Y gets pyxform's relevance, ${q} = 'other' or selected(${q}, 'other'). This keeps lstsv2ddi's output identical to xlsform2ddi's for the explicit pair.
• Docs: README, ARCHITECTURE and src/pipelines/README.md no longer say DDI drops logic. They now list what is still missing: defaults, appearances, groups and order (DDI round trips: keep question order, every group, and notes apart from hints #152, DDI round trips: every form field in standard DDI where possible, cdl: notes only for the rest #153).

For DDI readers

The change only adds elements and relaxes one Schematron rule; nothing existing moves. qwacback (qwacback#37) stores <universe> and the typed notes.

Checks

• vitest: 1236 passed. This includes the new tests/ts/unit/ddi/logic.test.ts.
• pytest validation and codegen: 127 passed, 3 xfailed. XSD and Schematron pass on every snapshot except the two already listed in KNOWN_INVALID, which fail with the same errors as before.
• npm run validate and the drift check are clean.

🤖 Generated with Claude Code