fix: template query param stripped during login views (#6677)

Fixes issue where query params from
https://github.com/Comfy-Org/ComfyUI_frontend/pull/6593 are stripped
during the login/signup views/flow by storing initial params in session
storage via router plugin.



https://github.com/user-attachments/assets/51642e8c-af5c-43ef-ab7d-133bc7e511aa




┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-6677-fix-template-query-param-stripped-during-login-views-2aa6d73d365081a1bdc7d22b35f72a77)
by [Unito](https://www.unito.io)

tests-ui/tests/platform/workflow/templates/composables/useTemplateUrlLoader.test.ts

@@ -12,6 +12,10 @@ import { useTemplateUrlLoader } from '@/platform/workflow/templates/composables/
  * - Input validation for template and source parameters
  */
 
+const preservedQueryMocks = vi.hoisted(() => ({
+  clearPreservedQuery: vi.fn()
+}))
+
 // Mock vue-router
 let mockQueryParams: Record<string, string | undefined> = {}
 const mockRouterReplace = vi.fn()
@@ -25,6 +29,11 @@ vi.mock('vue-router', () => ({
   }))
 }))
 
+vi.mock(
+  '@/platform/navigation/preservedQueryManager',
+  () => preservedQueryMocks
+)
+
 // Mock template workflows composable
 const mockLoadTemplates = vi.fn().mockResolvedValue(true)
 const mockLoadWorkflowTemplate = vi.fn().mockResolvedValue(true)
@@ -88,6 +97,7 @@ describe('useTemplateUrlLoader', () => {
       'flux_simple',
       'default'
     )
+    expect(preservedQueryMocks.clearPreservedQuery).toHaveBeenCalledTimes(1)
   })
 
   it('uses default source when source param is not provided', async () => {