Fixes#618
## Changes
Add stack depth validation in processExecIf() so asymmetric EXEC.IF branches (where one branch pushes more values than the other) throw an explicit error instead of silently padding with '0'. Error messages identify both branch depths for DYADIC and BOOLEAN stacks. Removed dead-code '0'/'false' fallbacks in buildAssignments and reconstruction. Updated existing unbalanced-branch tests to expect errors; added regression tests for error message content and BOOLEAN mismatch. All existing seed files (optimizer_v3.push3, optimizer_seed.push3) continue to transpile.
Co-authored-by: openhands <openhands@all-hands.dev>
Reviewed-on: https://codeberg.org/johba/harb/pulls/1033
Reviewed-by: Disinto_bot <disinto_bot@noreply.codeberg.org>
Add TypeScript unit test suite for the Push3 transpiler using Node's
built-in test runner (node:test) with tsx. 47 tests across 12 suites
covering parser, stack underflow/overflow, EXEC.IF balanced/unbalanced/
nested branching, arithmetic, boolean ops, name binding, and integration.
Update CI to run `npm test` (which now includes unit tests + existing
bash tests) and scope transpiler-tests step to only trigger on changes
to tools/push3-transpiler/**.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
