decide between raw cdp fetch-domain request interception and playwright's page.route() for mocking network requests

Steps

1. default to page.route()/context.route() for request mocking in Playwright tests, since it is the documented, cross-browser (Chromium/Firefox/WebKit) API with route.fulfill()/route.continue()/route.abort()
2. reach for a raw CDPSession and the Fetch domain only when a Chromium-specific capability is needed that route() does not expose, such as low-level response body streaming or auth challenge handling outside Playwright's model
3. if using CDP directly, call session.send('Fetch.enable') with the relevant request patterns and handle Fetch.requestPaused events manually
4. weigh that CDP-based interception ties the test to Chromium only, while route() keeps the test portable across browser engines
5. prefer combining both only when necessary -- e.g. route() for behavior assertions and a scoped CDP session for one-off protocol-level debugging