Suggestion - add pexpect e2e tests to reduce manual testing

[zem00n]

First of all - thanks for creating this project. I have a suggestion -

If you use coding agent for this project that would enable that agent to troubleshoot and fix issues that are not reproducible in unit tests.

In general probably we can create airflow environment in a docker or something else with mocked data(db) and run e2e tests for that snapshot

How pexpect tests look like:

def test_create_spark_ui(log_file):
    """Create Spark UI for selected job and verify message appears."""
    child = start_child(log_file)
    # Enter clusters view
    child.expect_exact(["Virtual Clusters"], timeout=DEFAULT_TIMEOUT)

    # Enter first cluster
    child.send("\r")

    # Jobs view should render
    child.expect_exact(["Test Spark Job 1"], timeout=DEFAULT_TIMEOUT)

Let me know your thoughts