Add telemetry for entering linear mode (#8263)

Standard disclaimer: Telemetry only applies on cloud builds

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8263-Add-telemetry-for-entering-linear-mode-2f16d73d3650819ea53efeeb562ea095)
by [Unito](https://www.unito.io)

src/composables/useCoreCommands.ts

@@ -1235,8 +1235,11 @@ export function useCoreCommands(): ComfyCommand[] {
       id: 'Comfy.ToggleLinear',
       icon: 'pi pi-database',
       label: 'Toggle Simple Mode',
-      function: () => {
+      function: (metadata?: Record<string, unknown>) => {
+        const source =
+          typeof metadata?.source === 'string' ? metadata.source : 'keybind'
         const newMode = !canvasStore.linearMode
+        if (newMode) useTelemetry()?.trackEnterLinear({ source })
         app.rootGraph.extra.linearMode = newMode
         workflowStore.activeWorkflow?.changeTracker?.checkState()
         canvasStore.linearMode = newMode