fix(merge): resolve conflicts from master; keep WDA warmup + real healthy() check

sidecar/src/main/kotlin/dev/sanderling/sidecar/DriverBackend.kt

@@ -568,7 +568,7 @@ class IosDriverBackend(private val udid: String) : DriverBackend {
         driver.waitForAppToSettle(null, null, durationMillis.toInt())
     }
 
-    override fun healthy() = true
+    override fun healthy() = runCatching { driver.contentDescriptor(false); true }.getOrElse { false }
 
     override fun metrics(bundleId: String) = MetricsSample(0.0, 0L, 0L)
 }