feat: harden support, localize knowledge and add operator availability [skip ci]

Source-only publication of reviewed commit 64e96a7f423673dc29ad56485be9fc79bce8af1c.

Passed in isolation: focused frontend/backend tests, race checks, TypeScript typecheck, lint, Go compilation, Flowgram build, and deterministic SDK build/tests.

Not accepted as a production release: Next.js export/native assembly remains blocked by environment memory limits; browser interaction and MySQL staging acceptance remain unverified. No production server, database/schema, runtime configuration, deployment, release tag, or workflow execution was performed.

Expected source tree: 0a4a7528e9.

internal/pkg/eventbus/bus_test.go

@@ -1,3 +1,4 @@
+// Modified by the independent AgentDesk fork for support reliability and availability.
 package eventbus
 
 import (
@@ -197,3 +198,21 @@ func TestPublishAsyncAllowsReentrantPublishWithConcurrencyLimit(t *testing.T) {
 		t.Fatalf("expected reentrant async publish to complete")
 	}
 }
+
+func TestWaitJoinsNestedAsyncHandlersAndErrorCallbacks(t *testing.T) {
+	var handled atomic.Int64
+	bus := New[testEvent](WithAsyncConcurrency[testEvent](1), WithErrorHandler[testEvent](func(context.Context, error) {
+		handled.Add(1)
+	}))
+	bus.Subscribe(func(ctx context.Context, event testEvent) error {
+		if event.ID == 1 {
+			bus.PublishAsync(ctx, testEvent{ID: 2})
+		}
+		return errors.New("expected fixture error")
+	})
+	bus.PublishAsync(context.Background(), testEvent{ID: 1})
+	bus.Wait()
+	if handled.Load() != 2 {
+		t.Fatalf("Wait returned before nested work: %d error callbacks", handled.Load())
+	}
+}