The sidebar contract read a selector with indexOf, so it returned whichever
rule appeared earliest in the file. A responsive override added above the base
rule made the gate report a missing min-height that was never removed, which
blocked staging on a change that was correct.
Share one helper that strips comments, parses rule by rule, accepts a whole
group as the query, and returns the declarations of every matching rule. The
union also makes a negative assertion mean no rule may declare the property,
which is what these contracts intend.
The helper was duplicated in two files and had no tests of its own; it now has
regressions for each way it read the wrong block.
Co-authored-by: Cursor <cursoragent@cursor.com>
Jesse_Chen