Custom Select Module (customSelect.ts)

Module path: web_rviz/src/customSelect.ts

Purpose

Wraps native select elements with a styled, keyboard-accessible custom dropdown while keeping the native control as the source of truth.

refresh(): rebuilds the custom option list from the current native select state.
dispose(): removes enhancement markup and restores the original select in place.

Enhances one select element and returns its controller.

Refreshes an already-enhanced select if a controller exists.

The target select must already be attached to a parent element.
Each select gets at most one controller; repeated enhanceSelect() calls reuse the existing instance.
A MutationObserver watches option and disabled-state changes so the custom menu stays in sync.
Clicking outside the control or pressing Escape closes all open custom selects.
Selecting a new option updates the native value and dispatches a bubbling change event.