test: adapt SimulationController tests to callback-based UI wiring

Agent-Logs-Url: https://github.com/bedaHovorka/interlockSim/sessions/01419796-a691-46e1-ae10-8c1373a9ee18

Co-authored-by: bedaHovorka <5263405+bedaHovorka@users.noreply.github.com>

Author: Copilot

desktop-ui/src/main/kotlin/cz/vutbr/fit/interlockSim/gui/Frame.kt

@@ -26,6 +26,7 @@ import javax.swing.JFrame
 import javax.swing.JOptionPane
 import javax.swing.JPanel
 import javax.swing.JScrollPane
+import javax.swing.SwingUtilities
 import javax.swing.Timer
 
 /**
@@ -419,11 +420,17 @@ class Frame : JFrame(PROGRAM_FULL_NAME) {
 			}
 	}
 
+	/**
+	 * Execute [action] on EDT.
+	 *
+	 * Runs immediately if already on EDT; otherwise schedules asynchronously via
+	 * [javax.swing.SwingUtilities.invokeLater] to avoid blocking monitor/background threads.
+	 */
 	private fun runOnEdt(action: () -> Unit) {
-		if (javax.swing.SwingUtilities.isEventDispatchThread()) {
+		if (SwingUtilities.isEventDispatchThread()) {
 			action()
 		} else {
-			javax.swing.SwingUtilities.invokeLater(action)
+			SwingUtilities.invokeLater(action)
 		}
 	}
 

desktop-ui/src/main/kotlin/cz/vutbr/fit/interlockSim/gui/SimulationController.kt

@@ -35,10 +35,13 @@ import java.beans.PropertyChangeListener
  *   nulls it.
  * - Callbacks are invoked on whichever thread performs the lifecycle change.
  *
- * @param onStateChanged Callback for lifecycle state updates.
- * @param onSpeedChanged Callback for speed indicator updates.
- * @param onCompleted Callback invoked when the simulation finishes naturally.
- *   Defaults to a no-op.
+ * @param onStateChanged Callback for lifecycle state updates. Invoked on the same
+ *   thread that performs the state change (caller thread for [start]/[stop], monitor
+ *   thread for natural completion).
+ * @param onSpeedChanged Callback for speed indicator updates. Invoked on the thread
+ *   that emits the speed change; callers are responsible for EDT marshalling as needed.
+ * @param onCompleted Callback invoked when the simulation finishes naturally on the
+ *   monitor thread. Defaults to a no-op.
  * @since 2026-04-20 (extracted from Frame for testability)
  * @see Frame
  */

desktop-ui/src/test/kotlin/cz/vutbr/fit/interlockSim/gui/SimulationControllerTest.kt

@@ -680,6 +680,13 @@ class SimulationControllerTest {
 			onCompleted = onCompleted
 		)
 
+	/**
+	 * Execute [action] on EDT synchronously for deterministic assertions in unit tests.
+	 *
+	 * Unlike the production callback wiring pattern (which dispatches asynchronously),
+	 * this helper blocks until EDT work completes. That makes follow-up assertions
+	 * observe final state without timing races.
+	 */
 	private fun runOnEdtSync(action: () -> Unit) {
 		if (SwingUtilities.isEventDispatchThread()) {
 			action()