Support for deferred action invocations in plan

We encovered that deferred action invocations don't get provider
addresses, which prevents us from loading the schema. That being said, I
think it shouldn't be an issue, but will come back to revisit this as we
build the support end to end.

Add a test for deferred actions support

internal/stacks/stackplan/from_plan.go

@@ -207,6 +207,32 @@ func FromPlan(ctx context.Context, config *configs.Config, plan *plans.Plan, ref
 		})
 	}
 
+	// Handle deferred action invocations from the plan
+	for _, deferredAction := range plan.DeferredActionInvocations {
+		invocation := deferredAction.ActionInvocationInstanceSrc
+		
+		if invocation == nil {
+			continue
+		}
+
+		// For deferred actions, the provider address is typically empty because
+		// actions are deferred before being fully evaluated. We create the planned
+		// change without schema since we can't fetch it without a provider address.
+		plannedActionInvocation := PlannedChangeActionInvocationInstancePlanned{
+			ActionInvocationAddr: stackaddrs.AbsActionInvocationInstance{
+				Component: producer.Addr(),
+				Item:      invocation.Addr,
+			},
+			Invocation:         invocation,
+			Schema:             providers.ActionSchema{}, // Empty schema for deferred actions
+			ProviderConfigAddr: invocation.ProviderAddr,  // Will be empty, that's expected
+		}
+		changes = append(changes, &PlannedChangeDeferredActionInvocation{
+			DeferredReason:          deferredAction.DeferredReason,
+			ActionInvocationPlanned: plannedActionInvocation,
+		})
+	}
+
 	// We also need to catch any objects that exist in the "prior state"
 	// but don't have any actions planned, since we still need to capture
 	// the prior state part in case it was updated by refreshing during

internal/stacks/stackruntime/helper_test.go

@@ -443,6 +443,8 @@ func plannedChangeSortKey(change stackplan.PlannedChange) string {
 		return "function-results"
 	case *stackplan.PlannedChangeActionInvocationInstancePlanned:
 		return change.ActionInvocationAddr.String()
+	case *stackplan.PlannedChangeDeferredActionInvocation:
+		return "deferred:" + change.ActionInvocationPlanned.ActionInvocationAddr.String()
 	default:
 		// This is only going to happen during tests, so we can panic here.
 		panic(fmt.Errorf("unrecognized planned change type: %T", change))

internal/stacks/stackruntime/plan_test.go

@@ -6573,15 +6573,33 @@ func TestPlanWithDeferredActionInvocation(t *testing.T) {
 		return plannedChangeSortKey(gotChanges[i]) < plannedChangeSortKey(gotChanges[j])
 	})
 
-	// Find the deferred action invocation in the changes
+	// First, let's verify the resource was actually deferred
+	var foundDeferredResource bool
+	var foundNormalActionInvocation bool
 	var foundDeferredAction bool
+	
 	for _, change := range gotChanges {
-		if _, ok := change.(*stackplan.PlannedChangeDeferredActionInvocation); ok {
+		switch c := change.(type) {
+		case *stackplan.PlannedChangeDeferredResourceInstancePlanned:
+			foundDeferredResource = true
+			t.Logf("Found deferred resource: %s", c.ResourceInstancePlanned.ResourceInstanceObjectAddr)
+		case *stackplan.PlannedChangeActionInvocationInstancePlanned:
+			foundNormalActionInvocation = true
+			t.Logf("Found normal action invocation: %s", c.ActionInvocationAddr)
+		case *stackplan.PlannedChangeDeferredActionInvocation:
 			foundDeferredAction = true
-			break
+			t.Logf("Found deferred action invocation: %s", c.ActionInvocationPlanned.ActionInvocationAddr)
 		}
 	}
 
+	if !foundDeferredResource {
+		t.Error("Expected to find a deferred resource, but none was found")
+	}
+
+	if foundNormalActionInvocation {
+		t.Error("Action invocation should be deferred, not appearing as a normal invocation")
+	}
+
 	if !foundDeferredAction {
 		t.Error("Expected to find a deferred action invocation in the plan changes, but none was found")
 		t.Logf("Got %d changes:", len(gotChanges))

internal/stacks/stackruntime/testdata/mainbundle/test/deferred-action/main.tf

@@ -18,7 +18,7 @@ variable "defer" {
   type = bool
 }
 
-# Action that should be invoked when resource is created
+# Simple action
 action "testing_action" "notify" {
   config {
     message = "resource created with id ${var.id}"