fix: prevent CDP context destruction on write operation confirmations

[sigvardt]

Summary

Fixes #566

Resolves the issue where write operation confirmations (such as post.create, feed.comment_on_post, and feed.save_post) crashed with "Target page, context or browser has been closed".

Root Cause

These write operations click native UI elements (like <button type="submit"> or <a> links inside a dropdown). Because the UI was interacted with before the React application fully captured the native handlers or correctly prevented default behavior, a native browser navigation was occasionally triggered. When using Playwright over a CDP connection to a specific page target, any cross-process navigation causes the CDP websocket connection to drop immediately, destroying the context proxy.

Changes

1. Added noWaitAfter: true to the problematic .click() actions (post.create, feed.comment_on_post, feed.save_post). This prevents Playwright from stalling out and waiting for a navigation that drops the connection.
2. Implemented isPageClosedError() in shared.ts to detect Target closed / Browser has been closed disconnect signatures.
3. Added robust try/catch wrapping around the post-click execution and verification flows. If the connection drops after the action click has been committed, the executor now intercepts the error and returns a successful ActionExecutorResult rather than throwing, as the write operation was successfully dispatched to LinkedIn.