Non-browser commands (`browser: false`) ran without any timeout
protection, even when `timeoutSeconds` was explicitly set. This wraps
the non-browser execution path with `runWithTimeout()` when the
adapter defines a positive `timeoutSeconds`.
Also adds an optional `hint` parameter to `TimeoutError` so the
non-browser path shows a relevant suggestion instead of the
browser-specific `OPENCLI_BROWSER_COMMAND_TIMEOUT` env var hint.