The 'mass noun' linter wrongly flags "both" before lists.

**What got flagged?**

**Why is this incorrect?**

Because the noun "readability" is not alone but is followed by "and" and another noun, making "both" correct.

Reproduce the reported warning for "both" before a coordinated list, then locate the mass noun linter rule and its existing tests. Check how the rule handles a noun followed by "and" and another noun; done means the valid construction is no longer flagged while the rule's intended warnings remain covered by tests.

Written by the indexing model from the issue text.