Make tests that wait for concurrent work wait on the event or a condition with a long deadline (issue 1814)

A test that slept a fixed time and then asserted what a goroutine, process or
watcher did failed under the checker's load. Each now waits for its positive
evidence (a started baseline, a call counted, a state reached) within 30 s, and
the concurrency-limit tests meet at a barrier instead of overlapping by sleep.

Claude-Session: https://claude.ai/code/session_01NcbgfJ9Gum47zkFKWRaovL

modules/mesh-provisioner-client/cmd/mesh-provisioner-client/asks_test.go

@@ -39,7 +39,7 @@ func aToolRunner(t *testing.T, b *aBus) *toolRunner {
 func (r *toolRunner) ask(body string) Answered {
 	r.t.Helper()
 	var a Answered
-	deadline := time.Now().Add(10 * time.Second)
+	deadline := time.Now().Add(30 * time.Second)
 	for {
 		msg, err := r.nc.Request(AskSubject(node), []byte(body), 2*time.Second)
 		if err == nil {
@@ -83,7 +83,7 @@ func (b *aBus) placed(t *testing.T, module string) {
 
 func until(t *testing.T, heard chan string, want string) {
 	t.Helper()
-	deadline := time.After(10 * time.Second)
+	deadline := time.After(30 * time.Second)
 	for {
 		select {
 		case got := <-heard:

modules/mesh-provisioner-client/cmd/mesh-provisioner-client/client_test.go

@@ -404,10 +404,10 @@ func aClient(t *testing.T, b *aBus, e *engine, state string) (*Client, func()) {
 
 func eventually(t *testing.T, what string, ok func() bool) {
 	t.Helper()
-	deadline := time.Now().Add(10 * time.Second)
+	deadline := time.Now().Add(30 * time.Second)
 	for !ok() {
 		if time.Now().After(deadline) {
-			t.Fatalf("not within 10s: %s", what)
+			t.Fatalf("not within 30s: %s", what)
 		}
 		time.Sleep(20 * time.Millisecond)
 	}
@@ -502,7 +502,8 @@ func TestNatsAChangeRefillsWritesOnceAndTheProgramTakesIt(t *testing.T) {
 	// again (ADR 0349 clause 5), which answers unchanged, so the program is not reloaded for it.
 	b.config(t, "dunst", "font-size", "15")
 	b.config(t, "dunst", "geometry", `"300x5"`)
-	time.Sleep(300 * time.Millisecond)
+	eventually(t, "the node-engine is asked for the file again by each fill", func() bool { _, asked := e.counts(dunstrc); return asked >= 3 })
+	time.Sleep(300 * time.Millisecond) // any stray extra write would come now
 	if moved, asked := e.counts(dunstrc); moved != 2 || asked != 3 {
 		t.Errorf("two values wrote dunstrc %d times (asked %d); want 2 and 3: the program is reloaded once a change, "+
 			"the file asked again each fill", moved, asked)

modules/mesh-provisioner-client/cmd/mesh-provisioner-client/socket_integration_test.go

@@ -83,7 +83,7 @@ func TestWatchSocketWakesWhenTheSocketIsMadeAndWhenItsDirectoryReturns(t *testin
 		t.Helper()
 		select {
 		case <-up:
-		case <-time.After(5 * time.Second):
+		case <-time.After(30 * time.Second):
 			t.Fatalf("no wake for %s", what)
 		}
 	}