test: replace expect() with waitFor() in fixture files

Per Playwright best practices, assertions belong in tests, not fixtures.
Fixture methods should use waitFor() for preconditions instead.

- vueNodeFixtures.ts: setTitle(), cancelTitleEdit() use waitFor()
- Topbar.ts: closeTopbarMenu() uses waitFor({ state: 'hidden' })
- ComfyPage.ts: ConfirmDialog.click(), closeDialog(), clickDialogButton(),
  closeToasts() all converted to waitFor()
- templates.ts: renamed waitForMinimumCardCount to expectMinimumCardCount
  to clarify it contains an assertion (uses expect().toPass() pattern)

Amp-Thread-ID: https://ampcode.com/threads/T-019c11f8-acd2-7429-8bec-525ad47a47c4
Co-authored-by: Amp <amp@ampcode.com>

browser_tests/fixtures/components/Topbar.ts

@@ -1,5 +1,4 @@
 import type { Locator, Page } from '@playwright/test'
-import { expect } from '@playwright/test'
 
 export class Topbar {
   private readonly menuLocator: Locator
@@ -122,7 +121,7 @@ export class Topbar {
    */
   async closeTopbarMenu() {
     await this.page.locator('body').click({ position: { x: 300, y: 10 } })
-    await expect(this.menuLocator).not.toBeVisible()
+    await this.menuLocator.waitFor({ state: 'hidden' })
   }
 
   /**