Ensure terminal E2E probes run reliably on Windows CI, where the shell
does not always inherit setup-node's PATH.
- Add `nodeTerminalCommand` helper to resolve and quote `process.execPath`
for either POSIX shells or PowerShell depending on the platform.
- Update terminal tests and probes to use the new helper instead of
hardcoded `node` invocations.
* Stabilize terminal e2e tests on Windows ConPTY
Windows ConPTY can drop or reorder the tail of large synchronized terminal
frames or stdout writes when they are written all at once or when the process
exits too quickly.
* Wait for PTY shell readiness before running test scripts.
* Chunk large table writes line-by-line and yield with a short timeout on
Windows to let the stream drain.
* Add and poll for a synchronized frame tail marker to ensure the entire
content is rendered before proceeding.
* Remove flaky preflight shell echo in terminal emoji scroll test
The Ctrl+C/Ctrl+U preflight keys sent by `waitForPtyShellEcho` can race
Windows ConPTY startup and eat subsequent test input. Remove this wait
and rely on the fixture marker as the readiness signal instead.
Jinjing
Neil