[Feature] Add static HTML test pages for deterministic integration testing

[thalissonvs]

To improve the reliability of the project, we should create static HTML and CSS pages that live inside the project itself. That way, we’re not depending on external servers or network conditions, which makes the tests faster and fully deterministic. The goal is to cover scenarios like opening and closing the browser, querying elements, performing clicks, handling navigation, and other core behaviors, all within a controlled environment. These pages could be stored in a dedicated folder and used during test runs via local file access or a lightweight internal server if needed. This approach would give us much more confidence in the stability of the tool and avoid flaky behavior caused by unpredictable remote content.

Potential structure:

tests/
  integration/
    test_open_close_browser.py
    ...
  pages/
    basic_interaction.html
    dom_mutation.html
    form_submission.html
    ...