feat: track app mode entry and shared workflow loading (#9720)

## Summary

- Track entering app mode from template URL (`source: template_url`) and
default view dialog (`source: default_view_dialog`)
- Tag shared workflow loads with `openSource: 'shared'` instead of
defaulting to `'unknown'`
- Rename telemetry event from `app:toggle_linear_mode` to
`app:app_mode_opened`

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-9720-feat-track-app-mode-entry-and-shared-workflow-loading-31f6d73d365081af8c6ae3247a50cf3f)
by [Unito](https://www.unito.io)

---------

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

src/platform/telemetry/providers/cloud/MixpanelTelemetryProvider.ts

@@ -15,6 +15,7 @@ import type {
   AuthMetadata,
   CreditTopupMetadata,
   EnterLinearMetadata,
+  ShareFlowMetadata,
   ExecutionContext,
   ExecutionTriggerSource,
   ExecutionErrorMetadata,
@@ -362,6 +363,10 @@ export class MixpanelTelemetryProvider implements TelemetryProvider {
     this.trackEvent(TelemetryEvents.ENTER_LINEAR_MODE, metadata)
   }
 
+  trackShareFlow(metadata: ShareFlowMetadata): void {
+    this.trackEvent(TelemetryEvents.SHARE_FLOW, metadata)
+  }
+
   trackPageVisibilityChanged(metadata: PageVisibilityMetadata): void {
     this.trackEvent(TelemetryEvents.PAGE_VISIBILITY_CHANGED, metadata)
   }

src/platform/telemetry/providers/cloud/PostHogTelemetryProvider.test.ts

@@ -85,7 +85,8 @@ describe('PostHogTelemetryProvider', () => {
         autocapture: false,
         capture_pageview: false,
         capture_pageleave: false,
-        persistence: 'localStorage+cookie'
+        persistence: 'localStorage+cookie',
+        debug: false
       })
     })
 

src/platform/telemetry/providers/cloud/PostHogTelemetryProvider.ts

@@ -8,6 +8,7 @@ import type { RemoteConfig } from '@/platform/remoteConfig/types'
 import type {
   AuthMetadata,
   EnterLinearMetadata,
+  ShareFlowMetadata,
   ExecutionContext,
   ExecutionErrorMetadata,
   ExecutionSuccessMetadata,
@@ -104,7 +105,8 @@ export class PostHogTelemetryProvider implements TelemetryProvider {
               autocapture: false,
               capture_pageview: false,
               capture_pageleave: false,
-              persistence: 'localStorage+cookie'
+              persistence: 'localStorage+cookie',
+              debug: import.meta.env.VITE_POSTHOG_DEBUG === 'true'
             })
             this.isInitialized = true
             this.flushEventQueue()
@@ -346,6 +348,10 @@ export class PostHogTelemetryProvider implements TelemetryProvider {
     this.trackEvent(TelemetryEvents.ENTER_LINEAR_MODE, metadata)
   }
 
+  trackShareFlow(metadata: ShareFlowMetadata): void {
+    this.trackEvent(TelemetryEvents.SHARE_FLOW, metadata)
+  }
+
   trackPageVisibilityChanged(metadata: PageVisibilityMetadata): void {
     this.trackEvent(TelemetryEvents.PAGE_VISIBILITY_CHANGED, metadata)
   }