fix(eslint): support pageExtensions in no-html-link-for-pages rule

[malkovitc]

Summary

Add support for custom pageExtensions option in the no-html-link-for-pages ESLint rule. This allows projects using custom page extensions (e.g., .page.tsx, .page.ts) to properly detect internal routes.

Changes

• Add pageExtensions option to rule schema
• Update url.ts to accept pageExtensions parameter
• Create dynamic regex patterns based on provided extensions
• Add tests for custom page extensions

Usage

// .eslintrc.js
module.exports = {
  rules: {
    '@next/next/no-html-link-for-pages': [
      'error',
      {
        pagesDir: 'src/pages',
        pageExtensions: ['page.tsx', 'page.ts', 'page.jsx', 'page.js']
      }
    ]
  }
}

How tested

• Added 3 new test cases for custom page extensions
• All 26 tests pass

Fixes #53473

[nextjs-bot]

Allow CI Workflow Run

• approve CI run for commit: 0a3f4ef

Note: this should only be enabled once the PR is ready to go and can only be enabled by a maintainer

[nextjs-bot]

Allow CI Workflow Run

• approve CI run for commit: 0a3f4ef

Note: this should only be enabled once the PR is ready to go and can only be enabled by a maintainer