Test report SVG colors in light theme

[Copilot]

Report SVGs relied on theme variables but lacked coverage for light-mode values. This adds contract coverage for both color schemes.

• Theme coverage

  • Verifies --success, --danger, and --cancelled are defined in dark and light themes.
  • Confirms chart SVG strokes resolve through those variables.

• Current-color SVGs

  • Verifies the sidebar brand SVG uses currentColor.
  • Confirms --fg is provided by both themes.

assert.match(report, new RegExp(
  `\\.${svgClass}\\s*\\{\\s*stroke:\\s*var\\(--${name}\\)`,
));

• Fixes Light themed #8