Add clock-less delay overload

[sergeysova]

Add delay({ timeout, target }) which returns a unit suitable for sample target arrays. Covers typing, runtime behavior, fork scope, and documentation.

Closes #285

---

Note

Medium Risk
Adds a new runtime code path and TypeScript overloads for delay that change dispatch behavior when source is omitted; risk is moderate due to potential overload/behavioral edge cases, though covered by new tests and typings.

Overview
Adds a new delay({ timeout, target }) overload that creates and returns a trigger Event, which when called schedules the provided target unit(s) after the resolved timeout (number/store/function).

Updates delay’s implementation to branch when source is omitted, introduces a dedicated delayWithoutSource path, and adjusts typings/tests (including forked-scope behavior), plus documents the new overload in src/delay/readme.md.

^{Written by Cursor Bugbot for commit f125472. This will update automatically on new commits. Configure here.}

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}