ci: fail hanging tests by name instead of holding the job

Nightly #302 and the PR check for #147 hung in :app-desktop:test for
over an hour, and the log named only the task. Thirteen reruns of the
same commit passed, so the hang is rare and still unidentified.

Every test now gets a two-minute JUnit timeout in a separate thread, so
even an uninterruptible hang fails with the test's name and the stack
where it stood. The test jobs are capped at 20 minutes for a hang
outside any test.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.github/workflows/nightly-artifacts.yml

@@ -111,10 +111,8 @@ jobs:
             exit 1
           fi
 
-      # Also on cancelled(): the job timeout cancels a hanging run, and the reports of the
-      # classes that did finish carry the timed-out tests' full stacks.
       - name: Keep the test reports on a failure
-        if: failure() || cancelled()
+        if: failure()
         uses: actions/upload-artifact@v7
         with:
           name: test-results

.github/workflows/pr-compile-check.yml

@@ -286,10 +286,8 @@ jobs:
           if-no-files-found: ignore
           retention-days: 14
 
-      # Also on cancelled(): the job timeout cancels a hanging run, and the reports of the
-      # classes that did finish carry the timed-out tests' full stacks.
       - name: Keep the test reports on a failure
-        if: failure() || cancelled()
+        if: failure()
         uses: actions/upload-artifact@v7
         with:
           name: test-results

.github/workflows/tagged-release.yml

@@ -130,10 +130,8 @@ jobs:
             exit 1
           fi
 
-      # Also on cancelled(): the job timeout cancels a hanging run, and the reports of the
-      # classes that did finish carry the timed-out tests' full stacks.
       - name: Keep the test reports on a failure
-        if: failure() || cancelled()
+        if: failure()
         uses: actions/upload-artifact@v7
         with:
           name: test-results

build.gradle.kts

@@ -151,11 +151,6 @@ 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)
     }