fix(schema-compiler): multi_stage leaf measure missing FROM clause by TheRoot-1 · Pull Request #10550 · cube-js/cube

@TheRoot-1

When a multi_stage measure's sql references a raw column with no measure
dependencies, fromMeasures is null so fromSubQuery is never built, leaving
fromSql null. The existing error check then throws "lacks FROM clause".

Add a fallback: when fromSql is null but withQuery.measures is non-empty,
build a subquery directly from the cube's own table instead of failing.

Fixes: cube-js#10549
Related: cube-js#9241