refactor: convert sequential.js to TypeScript

Fixes #661 (partial - 1 file)

- Renamed sequential.js to sequential.ts
- Added TypeScript type annotation to changeClockEnable parameter (val: boolean)
- Added return type annotation (void)
- No logic changes, only type safety improvements

Author: pantha704

src/simulator/src/sequential.js src/simulator/src/sequential.tssrc/simulator/src/sequential.js renamed to src/simulator/src/sequential.ts

@@ -1,10 +1,10 @@
-import { scheduleUpdate, play, updateCanvasSet } from './engine'
 import { simulationArea } from './simulationArea'
 
 /**
  * a global function as a helper for simulationArea.changeClockEnable
  * @category sequential
+ * @param val - boolean value to enable/disable clock
  */
-export function changeClockEnable(val) {
+export function changeClockEnable(val: boolean): void {
     simulationArea.clockEnabled = val
 }