- Enhanced `wait()` in browser tools to accept a predicate function in addition to milliseconds.
- Implemented automatic polling with configurable timeout and interval, resolving with the first truthy value.
- Throws a descriptive `ToolError` on timeout instead of waiting for the full execution deadline.
- Added comprehensive unit tests to verify polling behavior, cancellation, and error handling.
- Added comprehensive test suite for `postmortem` utility error handling, covering cleanup symbol marking, cause chain depth validation, and process exception suppression.
- Added tests for `browser-run-cancellation` ensuring proper `unhandledRejection` suppression and correct `ToolAbortError` propagation during teardown.
- Implemented `collectUnhandledRejections` helper to verify silence of process-level rejections during async race conditions in browser runs.
- Added integration-style probe tests for `postmortem` to verify that marked cleanup errors allow process survival while unmarked ones remain fatal.
Wrapped cmux page, browser, and tab globals with per-run abort checks so stale continuations cannot reuse the long-lived CmuxTab after timeout.
Fixes#3964
can1357