Integration: Catchy.Selenium — WebDriver assertion surface

[olesme]

Goal

Provide a fluent async assertion surface for Selenium WebDriver element and page assertions.

Proposed API sketch

await Assert.That(driver).CurrentUrl().Contains(checkout);
await Assert.That(element).IsVisible().HasText(Submit);

Scope

• New package Catchy.Selenium targeting netstandard2.0;net8.0;net9.0
• Assertable surfaces: IWebDriver, IWebElement
• Async wrappers via WebDriverWait / IJavaScriptExecutor
• Smoke-test entry in tests/NuGetPackageSmoke
• Integration catalog entry in docs/integration-catalog.md

Out of scope for v1

• Page Object Model helpers (separate package)
• Grid / parallel session management

Prerequisite

Integration proposal approved via integration issue template.