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/utils/vueNodeFixtures.ts

@@ -1,4 +1,3 @@
-import { expect } from '@playwright/test'
 import type { Locator } from '@playwright/test'
 
 /** DOM-centric helper for a single Vue-rendered node on the canvas. */
@@ -40,7 +39,7 @@ export class VueNodeFixture {
   async setTitle(value: string): Promise<void> {
     await this.header.dblclick()
     const input = this.titleInput
-    await expect(input).toBeVisible()
+    await input.waitFor({ state: 'visible' })
     await input.fill(value)
     await input.press('Enter')
   }
@@ -48,7 +47,7 @@ export class VueNodeFixture {
   async cancelTitleEdit(): Promise<void> {
     await this.header.dblclick()
     const input = this.titleInput
-    await expect(input).toBeVisible()
+    await input.waitFor({ state: 'visible' })
     await input.press('Escape')
   }