fix(android): arbitrate op-failure probe off the reducer thread

Awaiting probeOnce() inline in the OpFailure branch blocked the single-consumer
reducer for the /healthz timeout, delaying a concurrent self-proving success
from snapping back to Healthy. Launch the probe instead so recovery stays fast.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

android/app/src/main/java/com/fabledsword/minstrel/connectivity/NetworkStatusController.kt

@@ -109,7 +109,10 @@ class NetworkStatusController @Inject constructor(
                 Intent.OpSuccess -> machine.onSuccess()
                 Intent.OpFailure -> {
                     machine.onOpFailure(now)
-                    probeOnce() // arbitrate: let /healthz decide if this is real
+                    // Arbitrate off the reducer thread: awaiting a stalled
+                    // /healthz here would block a concurrent self-proving
+                    // success from snapping us straight back to Healthy.
+                    scope.launch { probeOnce() }
                 }
             }
             emit(machine.health())