ci: print full stacks of failed tests and keep reports on a cancel (#151)

Nightly #303 named the hanging test, SelectedStationMessageUiVisual-
RenderingTest at scene.render(), but the short exception format showed
only that line, not the call that blocked below it. The job timeout
cancels the run, and the test reports were kept only on failure().

Failed tests now print their full stack, causes included, and the
reports are uploaded on cancelled() as well.

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>

build.gradle.kts

@@ -151,6 +151,11 @@ subprojects {
          */
         systemProperty("junit.jupiter.execution.timeout.default", "2m")
         systemProperty("junit.jupiter.execution.timeout.thread.mode.default", "SEPARATE_THREAD")
+        // The default short format prints only the first frame of each cause, which for a
+        // timed-out test is the line it hung in but not the call that blocked there.
+        testLogging {
+            exceptionFormat = org.gradle.api.tasks.testing.logging.TestExceptionFormat.FULL
+        }
         finalizedBy(checkTestUserHome)
     }