feat(core): Coordinate manual workflow activation and deactivation in multi-main scenario (#7643)

Followup to #7566 | Story: https://linear.app/n8n/issue/PAY-926

### Manual workflow activation and deactivation

In a multi-main scenario, if the user manually activates or deactivates
a workflow, the process (whether leader or follower) that handles the
PATCH request and updates its internal state should send a message into
the command channel, so that all other main processes update their
internal state accordingly:

- Add to `ActiveWorkflows` if activating
- Remove from `ActiveWorkflows` if deactivating
- Remove and re-add to `ActiveWorkflows` if the update did not change
activation status.

After updating their internal state, if activating or deactivating, the
recipient main processes should push a message to all connected
frontends so that these can update their stores and so reflect the value
in the UI.

### Workflow activation errors

On failure to activate a workflow, the main instance should record the
error in Redis - main instances should always pull activation errors
from Redis in a multi-main scenario.

### Leadership change

On leadership change...

- The old leader should stop pruning and the new leader should start
pruning.
- The old leader should remove trigger- and poller-based workflows and
the new leader should add them.

packages/editor-ui/src/Interface.ts

@@ -421,7 +421,25 @@ export type IPushData =
 	| PushDataRemoveNodeType
 	| PushDataTestWebhook
 	| PushDataExecutionRecovered
-	| PushDataWorkerStatusMessage;
+	| PushDataWorkerStatusMessage
+	| PushDataActiveWorkflowAdded
+	| PushDataActiveWorkflowRemoved
+	| PushDataWorkflowFailedToActivate;
+
+type PushDataActiveWorkflowAdded = {
+	data: IActiveWorkflowAdded;
+	type: 'workflowActivated';
+};
+
+type PushDataActiveWorkflowRemoved = {
+	data: IActiveWorkflowRemoved;
+	type: 'workflowDeactivated';
+};
+
+type PushDataWorkflowFailedToActivate = {
+	data: IWorkflowFailedToActivate;
+	type: 'workflowFailedToActivate';
+};
 
 type PushDataExecutionRecovered = {
 	data: IPushDataExecutionRecovered;
@@ -491,6 +509,19 @@ export interface IPushDataExecutionFinished {
 	retryOf?: string;
 }
 
+export interface IActiveWorkflowAdded {
+	workflowId: string;
+}
+
+export interface IActiveWorkflowRemoved {
+	workflowId: string;
+}
+
+export interface IWorkflowFailedToActivate {
+	workflowId: string;
+	errorMessage: string;
+}
+
 export interface IPushDataUnsavedExecutionFinished {
 	executionId: string;
 	data: { finished: true; stoppedAt: Date };

packages/editor-ui/src/components/WorkflowActivator.vue

@@ -119,7 +119,7 @@ export default defineComponent({
 				} else {
 					errorMessage = this.$locale.baseText(
 						'workflowActivator.showMessage.displayActivationError.message.errorDataNotUndefined',
-						{ interpolate: { message: errorData.error.message } },
+						{ interpolate: { message: errorData } },
 					);
 				}
 			} catch (error) {

packages/editor-ui/src/mixins/pushConnection.ts

@@ -291,6 +291,33 @@ export const pushConnection = defineComponent({
 				}
 			}
 
+			if (
+				receivedData.type === 'workflowFailedToActivate' &&
+				this.workflowsStore.workflowId === receivedData.data.workflowId
+			) {
+				this.workflowsStore.setWorkflowInactive(receivedData.data.workflowId);
+				this.workflowsStore.setActive(false);
+
+				this.showError(
+					new Error(receivedData.data.errorMessage),
+					this.$locale.baseText('workflowActivator.showError.title', {
+						interpolate: { newStateName: 'activated' },
+					}) + ':',
+				);
+
+				return true;
+			}
+
+			if (receivedData.type === 'workflowActivated') {
+				this.workflowsStore.setWorkflowActive(receivedData.data.workflowId);
+				return true;
+			}
+
+			if (receivedData.type === 'workflowDeactivated') {
+				this.workflowsStore.setWorkflowInactive(receivedData.data.workflowId);
+				return true;
+			}
+
 			if (receivedData.type === 'executionFinished' || receivedData.type === 'executionRecovered') {
 				// The workflow finished executing
 				let pushData: IPushDataExecutionFinished;

packages/editor-ui/src/stores/workflows.store.ts

@@ -10,7 +10,6 @@ import {
 } from '@/constants';
 import type {
 	ExecutionsQueryFilter,
-	IActivationError,
 	IExecutionDeleteFilter,
 	IExecutionPushResponse,
 	IExecutionResponse,
@@ -365,7 +364,7 @@ export const useWorkflowsStore = defineStore(STORES.WORKFLOWS, {
 			});
 		},
 
-		async getActivationError(id: string): Promise<IActivationError | undefined> {
+		async getActivationError(id: string): Promise<string | undefined> {
 			const rootStore = useRootStore();
 			return makeRestApiRequest(rootStore.getRestApiContext, 'GET', `/active/error/${id}`);
 		},
@@ -552,6 +551,9 @@ export const useWorkflowsStore = defineStore(STORES.WORKFLOWS, {
 			if (this.workflowsById[workflowId]) {
 				this.workflowsById[workflowId].active = true;
 			}
+			if (workflowId === this.workflow.id) {
+				this.setActive(true);
+			}
 		},
 
 		setWorkflowInactive(workflowId: string): void {
@@ -562,6 +564,9 @@ export const useWorkflowsStore = defineStore(STORES.WORKFLOWS, {
 			if (this.workflowsById[workflowId]) {
 				this.workflowsById[workflowId].active = false;
 			}
+			if (workflowId === this.workflow.id) {
+				this.setActive(false);
+			}
 		},
 
 		async fetchActiveWorkflows(): Promise<string[]> {