test(sw): stabilize Firefox hover, pixel and timing checks

- hover-stability-firefox: instant scroll and state waits instead of a fixed 60ms delay (smooth scroll in preview).
- integrated-visual, viewer-regression, theme-inheritance: deterministic Chromium raster flags, animations held at
  time 0, layout settle wait, integer instant scroll of inner panels; tolerance stays 0.
- text-weight: wait for the Viewer More panel instead of a fixed 200ms and fix the failure report.

packages/sw/tests/theme-inheritance.browser.mjs

@@ -27,7 +27,9 @@ const DEFAULT = '"Noto Sans KR", "Malgun Gothic", "Apple SD Gothic Neo", sans-se
 const results = []
 const check = (name, pass, detail = '') => { results.push({ name, result: pass ? 'PASS' : 'FAIL', detail }); console.log(`${pass ? 'PASS' : 'FAIL'}  ${name}${detail ? `  — ${detail}` : ''}`) }
 const errors = []
-const browser = await chromium.launch({ headless: true, executablePath: process.env.SW_CHROME_PATH ?? 'C:/Program Files/Google/Chrome/Application/chrome.exe' })
+// 2026-10-20: software raster without font hinting / subpixel positioning, as integrated-visual / viewer-regression: the
+// regression pass failed on varying Stories (Home Menu, Footer, Responsive More) on the same build, before and after the change.
+const browser = await chromium.launch({ headless: true, args: ['--disable-gpu', '--font-render-hinting=none', '--disable-font-subpixel-positioning', '--disable-lcd-text', '--force-color-profile=srgb'], executablePath: process.env.SW_CHROME_PATH ?? 'C:/Program Files/Google/Chrome/Application/chrome.exe' })
 const newPage = async (width = 1440, height = 1000) => {
   const page = await browser.newPage({ viewport: { width, height }, reducedMotion: 'reduce' })
   page.on('pageerror', error => errors.push(`${page.url()}: ${error.message}`))