fix(billing) - fix orphaned stripe subs (#20814)

Fix sentry issues
https://twenty-v7.sentry.io/issues/7203797925/?environment=prod&project=4507072499810304&query=is%3Aunresolved%20assigned%3Ame&referrer=issue-stream

An orphaned sub is a not "canceled" stripe sub with no matching
workspace

- Clean all orphaned sub (script not included in this PR)
- Ensure to soft delete > cancel stripe sub > check for not active sub >
hard delete in every workspace deletion flow

Bonus : 
- Remove dead code
- Update doc on RLS (to improve AI chat knowledge)

packages/twenty-server/src/engine/workspace-manager/workspace-cleaner/services/cleaner.workspace-service.ts

@@ -291,27 +291,49 @@ export class CleanerWorkspaceService {
     });
 
     if (workspaces.length !== 0) {
-      if (!dryRun) {
-        for (const workspace of workspaces) {
-          const userWorkspaces = await this.userWorkspaceRepository.find({
-            where: {
-              workspaceId: workspace.id,
-            },
-            withDeleted: true,
-          });
+      for (const workspace of workspaces) {
+        if (!isDefined(workspace.deletedAt)) {
+          this.logger.log(
+            `${dryRun ? 'DRY RUN - ' : ''}Soft deleting onboarding workspace ${workspace.id}`,
+          );
 
-          for (const userWorkspace of userWorkspaces) {
-            await this.workspaceService.handleRemoveWorkspaceMember(
-              workspace.id,
-              userWorkspace.userId,
-            );
+          if (!dryRun) {
+            const userWorkspaces = await this.userWorkspaceRepository.find({
+              where: {
+                workspaceId: workspace.id,
+              },
+              withDeleted: true,
+            });
+
+            for (const userWorkspace of userWorkspaces) {
+              await this.workspaceService.handleRemoveWorkspaceMember(
+                workspace.id,
+                userWorkspace.userId,
+              );
+            }
+
+            if (this.twentyConfigService.get('IS_BILLING_ENABLED')) {
+              await this.billingSubscriptionService.cancelSubscription(
+                workspace.id,
+              );
+            }
+
+            await this.workspaceService.deleteWorkspace(workspace.id, true);
           }
+        } else {
           if (this.twentyConfigService.get('IS_BILLING_ENABLED')) {
-            await this.billingSubscriptionService.deleteSubscriptions(
+            await this.billingSubscriptionService.assertSubscriptionCanceledOrNone(
               workspace.id,
             );
           }
-          await this.workspaceRepository.delete(workspace.id);
+
+          this.logger.log(
+            `${dryRun ? 'DRY RUN - ' : ''}Hard deleting onboarding workspace ${workspace.id}`,
+          );
+
+          if (!dryRun) {
+            await this.workspaceService.deleteWorkspace(workspace.id);
+          }
         }
       }