WS-394 - improve performance

[DmitryGron]

Resolves JIRA:

Summary

adding few suggested by lighthouse improvements and other experimental improvements
Changes

1. Image Priority for LCP
   Files:

• 'src/app/components/Image/index.tsx'
• 'src/app/components/ImageWithCaption/index.tsx'

Added conditional 'fetchPriority="high"' to hero images so browser downloads them first.

Code:
'tsx
// Image component - conditional fetchPriority in preload link
{...(fetchPriority && { fetchPriority })}

// ImageWithCaption - pass fetchPriority to lead images
fetchPriority={shouldPreloadLeadImage ? 'high' : undefined}
'

Why: Improves Largest Contentful Paint (LCP) by prioritizing hero image download.

---

2. Terser 2-Pass Compression
   File: 'webpack.config.client.js'

Enabled 2-pass Terser compression (default is 1 pass).

Code:
'js
compress: {
passes: 2,
}
'

Why: Better minification through multiple compression passes.

---

3. Bundle Size Baseline
   File: 'scripts/bundleSize/bundleSizeConfig.js'

Updated MAX_SIZE from 1312 to 1295 kB.

Why: Locks in 17KB bundle size reduction, prevents future regressions.

---

4. Test Snapshots
   Files: 10 integration test snapshot files

Updated snapshots for images now having 'fetchpriority="high"' attribute.

Why: Intentional DOM change from LCP optimization.

---

Result

• Bundle size: -17 kB (-1.3%)
• Hero images load faster ('fetchPriority="high"')
• Better minification (2-pass Terser compression)

Developer Checklist

• UX
  • UX Criteria met (visual UX & screenreader UX)
• Accessibility
  • Accessibility Acceptance Criteria met
  • Accessibility swarm completed
  • Component Health updated
  • P1 accessibility bugs resolved
  • P2/P3 accessibility bugs planned (if not resolved)
• Security
  • Security issues addressed
  • Threat Model updated
• Documentation
  • Docs updated (runbook, READMEs)
• Testing
  • Feature tested on relevant environments
• Comms
  • Relevant parties notified of changes

Testing

• Manual Testing required?
  • Local (Ready-For-Test, Local)
  • Test (Ready-For-Test, Test)
  • Preview (Ready-For-Test, Preview)
  • Live (Ready-For-Test, Live)
• Manual Testing complete?
  • Local
  • Test
  • Preview
  • Live

Additional Testing Steps

1. List the steps required to test this PR.

Useful Links

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