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/cli/src/services/redis/RedisServiceCommands.ts

@@ -6,7 +6,9 @@ export type RedisServiceCommand =
 	| 'restartEventBus'
 	| 'stopWorker'
 	| 'reloadLicense'
-	| 'reloadExternalSecretsProviders';
+	| 'reloadExternalSecretsProviders'
+	| 'workflowActiveStateChanged' // multi-main only
+	| 'workflowFailedToActivate'; // multi-main only
 
 /**
  * An object to be sent via Redis pub/sub from the main process to the workers.
@@ -50,6 +52,14 @@ export type RedisServiceWorkerResponseObject = {
 	| {
 			command: 'stopWorker';
 	  }
+	| {
+			command: 'workflowActiveStateChanged';
+			payload: {
+				oldState: boolean;
+				newState: boolean;
+				workflowId: string;
+			};
+	  }
 );
 
 export type RedisServiceCommandObject = {