fix: include intercepted payloads in diagnostic

[Astro-Han]

Description

Improve diagnostic output by surfacing already-captured interceptor payloads in the existing page.networkRequests field.

This keeps the follow-up for #810 minimal:

• collectPageState() now also reads page.getInterceptedRequests()
• intercepted payloads are wrapped as source: 'interceptor' entries and prepended to the existing network list
• diagnostic tests now cover inclusion, empty-interceptor fallback, and interceptor-read failures

Related issue: #810

Type of Change

• 🐛 Bug fix
• ✨ New feature
• 🌐 New site adapter
• 📝 Documentation
• ♻️ Refactor
• 🔧 CI / build / tooling

Checklist

• I ran the checks relevant to this PR
• I updated tests or docs if needed
• I included output or screenshots when useful

Documentation (if adding/modifying an adapter)

• Added doc page under docs/adapters/ (if new adapter)
• Updated docs/adapters/index.md table (if new adapter)
• Updated sidebar in docs/.vitepress/config.mts (if new adapter)
• Updated README.md / README.zh-CN.md when command discoverability changed
• Used positional args for the command's primary subject unless a named flag is clearly better
• Normalized expected adapter failures to CliError subclasses instead of raw Error

Screenshots / Output

$ npx tsc --noEmit
# exit 0

$ npm test
Test Files  44 passed (44)
     Tests  526 passed | 1 skipped (527)