Merge CB-577 follow-up: drop the target-keyed async index

asyncTasksByWaiter correlates an async question by the exact rendezvous
waiter, so the target-keyed set it replaced can no longer decide
anything. Keeping it meant two indexes of the same fact, one of them
ambiguous whenever a target has two accepted tickets.

The race the old test modelled by reflection is gone with it: identity
keys make 'some other task reached this target' unrepresentable, so
there is no longer a wrong task for the question to land on.

Also carries the criterion-1 doc correction, which is identical to
aac29d6 on a different parent.

bridged/src/test/java/dev/ltms/bridged/msg/MessageServiceTest.java

@@ -10,9 +10,6 @@ import dev.ltms.bridged.inject.Injector;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
-import java.lang.reflect.Field;
-import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.TimeUnit;
 
@@ -697,22 +694,10 @@ class MessageServiceTest {
     }
 
     @Test
-    @SuppressWarnings("unchecked")
     void asyncQuestionBelongsToTheTaskThatOwnsItsForwardWaiter() throws Exception {
         String first = messages.sendAsync(T, "first task");
         awaitWaiting();
 
-        // Model the resolveQuestion/markAsyncQuestion race: another accepted task reached the target set.
-        Field byTargetField = MessageService.class.getDeclaredField("asyncTasksByTarget");
-        byTargetField.setAccessible(true);
-        Map<String, Set<Object>> byTarget = (Map<String, Set<Object>>) byTargetField.get(messages);
-        Set<Object> targetTasks = byTarget.get(T);
-        Class<?> taskClass = Class.forName(MessageService.class.getName() + "$Task");
-        var constructor = taskClass.getDeclaredConstructor(String.class);
-        constructor.setAccessible(true);
-        targetTasks.clear();
-        targetTasks.add(constructor.newInstance(T));
-
         CompletableFuture<MessageService.AskResult> ask =
                 CompletableFuture.supplyAsync(() -> messages.ask(T, "which config?", 5000));
         assertEquals(MessageService.Phase.ASKING, awaitTicketPhase(first, MessageService.Phase.ASKING).phase());