feat: default to Getting Started category for new users in templates modal (#8599)

## Summary

Updates the templates modal to default to the "Getting Started" category
for new users.

## Changes

- Add `initialCategory` prop to `WorkflowTemplateSelectorDialog`
component
- Integrate `useNewUserService` in the dialog composable to detect
first-time users
- New users automatically see the "basics-getting-started" category
- Existing users continue to see "all" templates as default
- Allow explicit category override via options parameter

## Testing

- Added unit tests covering all scenarios (new user, non-new user,
undetermined, explicit override)
- 6 tests pass

Fixes COM-9146

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8599-feat-default-to-Getting-Started-category-for-new-users-in-templates-modal-2fd6d73d365081d4a5fad2abdb768269)
by [Unito](https://www.unito.io)

src/composables/useWorkflowTemplateSelectorDialog.test.ts

@@ -0,0 +1,132 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+const mockDialogService = vi.hoisted(() => ({
+  showLayoutDialog: vi.fn()
+}))
+
+const mockDialogStore = vi.hoisted(() => ({
+  closeDialog: vi.fn()
+}))
+
+const mockNewUserService = vi.hoisted(() => ({
+  isNewUser: vi.fn()
+}))
+
+const mockTelemetry = vi.hoisted(() => ({
+  trackTemplateLibraryOpened: vi.fn()
+}))
+
+vi.mock('@/services/dialogService', () => ({
+  useDialogService: () => mockDialogService
+}))
+
+vi.mock('@/stores/dialogStore', () => ({
+  useDialogStore: () => mockDialogStore
+}))
+
+vi.mock('@/services/useNewUserService', () => ({
+  useNewUserService: () => mockNewUserService
+}))
+
+vi.mock('@/platform/telemetry', () => ({
+  useTelemetry: () => mockTelemetry
+}))
+
+vi.mock(
+  '@/components/custom/widget/WorkflowTemplateSelectorDialog.vue',
+  () => ({
+    default: { name: 'MockWorkflowTemplateSelectorDialog' }
+  })
+)
+
+import { useWorkflowTemplateSelectorDialog } from './useWorkflowTemplateSelectorDialog'
+
+describe('useWorkflowTemplateSelectorDialog', () => {
+  beforeEach(() => {
+    vi.clearAllMocks()
+  })
+
+  describe('show', () => {
+    it('defaults to "all" category for non-new users', () => {
+      mockNewUserService.isNewUser.mockReturnValue(false)
+
+      const dialog = useWorkflowTemplateSelectorDialog()
+      dialog.show()
+
+      expect(mockDialogService.showLayoutDialog).toHaveBeenCalledWith(
+        expect.objectContaining({
+          props: expect.objectContaining({
+            initialCategory: 'all'
+          })
+        })
+      )
+    })
+
+    it('defaults to "basics-getting-started" category for new users', () => {
+      mockNewUserService.isNewUser.mockReturnValue(true)
+
+      const dialog = useWorkflowTemplateSelectorDialog()
+      dialog.show()
+
+      expect(mockDialogService.showLayoutDialog).toHaveBeenCalledWith(
+        expect.objectContaining({
+          props: expect.objectContaining({
+            initialCategory: 'basics-getting-started'
+          })
+        })
+      )
+    })
+
+    it('defaults to "all" when new user status is undetermined', () => {
+      mockNewUserService.isNewUser.mockReturnValue(null)
+
+      const dialog = useWorkflowTemplateSelectorDialog()
+      dialog.show()
+
+      expect(mockDialogService.showLayoutDialog).toHaveBeenCalledWith(
+        expect.objectContaining({
+          props: expect.objectContaining({
+            initialCategory: 'all'
+          })
+        })
+      )
+    })
+
+    it('uses explicit initialCategory when provided', () => {
+      mockNewUserService.isNewUser.mockReturnValue(true)
+
+      const dialog = useWorkflowTemplateSelectorDialog()
+      dialog.show('command', { initialCategory: 'custom-category' })
+
+      expect(mockDialogService.showLayoutDialog).toHaveBeenCalledWith(
+        expect.objectContaining({
+          props: expect.objectContaining({
+            initialCategory: 'custom-category'
+          })
+        })
+      )
+    })
+
+    it('tracks telemetry with source', () => {
+      mockNewUserService.isNewUser.mockReturnValue(false)
+
+      const dialog = useWorkflowTemplateSelectorDialog()
+      dialog.show('sidebar')
+
+      expect(mockTelemetry.trackTemplateLibraryOpened).toHaveBeenCalledWith({
+        source: 'sidebar'
+      })
+    })
+  })
+
+  describe('hide', () => {
+    it('closes the dialog', () => {
+      const dialog = useWorkflowTemplateSelectorDialog()
+      dialog.hide()
+
+      expect(mockDialogStore.closeDialog).toHaveBeenCalledWith({
+        key: 'global-workflow-template-selector'
+      })
+    })
+  })
+})