refactor(browser): type eval helper callbacks

[jun0315]

Description

Tightens the internal browser eval helper callback type by reusing BrowserEvaluateFunction instead of a local any[] callback signature.

This keeps the existing runtime behavior unchanged while removing one small internal any usage.

• 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

Screenshots / Output

npm test -- --project unit src/browser/utils.test.ts
Test Files  1 passed (1)
Tests       5 passed (5)

npm run typecheck -- --incremental false
passed