Issue: Add useClientPoint hook for cursor‑based tooltips and context menus

Issue: Add useClientPoint hook for cursor‑based tooltips and context menus: a task in LegoFlow-SWE (Harbor dataset). Currently, positioning a floating element at the cursor or a specific screen coordinate with @floating-ui/react requires verbose manual setup. There is no composable hook for common…

The task

Currently, positioning a floating element at the cursor or a specific screen coordinate with `@floating-ui/react` requires verbose manual setup. There is no composable hook for common use cases like mouse‑following tooltips, right‑click context menus, or any UI anchored to an `{x, y}` point rather than a DOM element.

Part of Lego-X/LegoFlow-SWE.