What changed

• implements Transformation Plan 0.2 conditional expressions, typed operands, and ordered schema state
• extends the SPSS frontend with bounded COMPUTE, conditional IF, formats, measurement levels, and EXECUTE
• applies conditional assignments in place while preserving dataset and physical table identity
• adds canonical validation, capability metadata, documentation, and conformance coverage
• keeps the adapter work under Unreleased, planned for Python 0.5.0

Why

Python v0.4 implements the product-neutral 0.1 plan but cannot express conditional row updates or the full 0.2 frontend contract. This branch implements that contract without adding copied datasets, staging snapshots, or an OpenStatSpec-managed history layer.

Integration dependencies

This branch is green in isolation but is not yet the final integration candidate.

1. Specification PR Harden transformation run recovery #6 must provide and publish openstatspec-specification==0.2.1.
2. Python lifecycle PR Recover minimal catalog and Dolt lifecycle integration #12 must land first.
3. Specification PR Fix transformation specification fixture lookup #5 must be reconciled with specification main; then this branch must pin its final immutable commit.
4. Rebase this branch on the lifecycle-enabled Python main, resolve overlapping API/capability/CI/catalog files, and run the complete service matrix.

The current specification commit pin is proposal-only and must not be used as a stable release claim.

Current validation

• conditional/frontend targeted suite: 54 passed
• full non-service suite: passed
• GitHub Actions run #156: green after the unreleased 0.5.0 version-line correction
• the branch remains an isolated pre-integration gate; combined lifecycle integration is still required

Readiness gate

Keep draft until the combined lifecycle + conditional branch passes Python 3.11–3.14, package smoke, PostgreSQL, MySQL, MariaDB, and Dolt fail-closed gates against the final specification commit.