CI: Gradle Managed Devices + GitHub Actions workflow

pixel7Api34 managed device runs instrumented tests headlessly on CI.
Three test-filter profiles (ci/parallel/full) mirror iOS xctestplan
variants. run_ui_tests.sh convenience wrapper.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

composeApp/build.gradle.kts

@@ -181,6 +181,15 @@ android {
     testOptions {
         unitTests.isIncludeAndroidResources = true
         unitTests.isReturnDefaultValues = true
+        managedDevices {
+            localDevices {
+                create("pixel7Api34") {
+                    device = "Pixel 7"
+                    apiLevel = 34
+                    systemImageSource = "aosp-atd"
+                }
+            }
+        }
     }
 }