Replace string interpolation in SetAttribute with Playwright's Evaluate
argument passing mechanism. This structurally eliminates the injection
surface — arbitrary name/value strings are safely passed as JavaScript
arguments rather than interpolated into the expression string.
The vulnerable escapeJavaScript helper (which only escaped \ and ') is
removed since it is no longer needed.
Closes#12
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>