feat: add telemetry for workflow save and default view (#9734)

Add two new telemetry events: `app:workflow_saved` (with `is_app` and
`is_new` metadata) and `app:default_view_set` for App Builder (with the
chosen view mode). Instrumented in workflowService and
useAppSetDefaultView.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9734-feat-add-telemetry-for-workflow-save-and-default-view-3206d73d3650814e8678f83c8419625f)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/platform/workflow/core/services/workflowService.ts

@@ -149,6 +149,8 @@ export const useWorkflowService = () => {
       await openWorkflow(tempWorkflow)
       await workflowStore.saveWorkflow(tempWorkflow)
     }
+
+    useTelemetry()?.trackWorkflowSaved({ is_app: isApp, is_new: true })
     return true
   }
 
@@ -189,6 +191,7 @@ export const useWorkflowService = () => {
       }
 
       await workflowStore.saveWorkflow(workflow)
+      useTelemetry()?.trackWorkflowSaved({ is_app: isApp, is_new: false })
     }
   }