fix: reset native button styles on Manage plan (FE-1668) (#15419)

## Summary

Fixes [FE-1668](https://linear.app/comfyorg/issue/FE-1668/): the
**Manage plan** item in the profile popover inherited native browser
`<button>` styling after #15266 changed it from a `<div>` to a
`<button>` for accessibility.

## Root cause

#15266 (`307c66ab5d`) added the correct keyboard and accessibility
semantics, but the button did not reset its native appearance. The
browser UA stylesheet therefore rendered a gray background, border, and
shrink-wrapped width that made this row visually inconsistent with the
neighboring menu items.

## Fix

Reset the native button appearance with `appearance-none`, `border-0`,
`bg-transparent`, `w-full`, and `text-left`. Preserve the existing hover
state and add an equivalent focus-visible state for keyboard users.

## AS IS

![Manage plan row with native gray button background and
border](https://ampcode.com/user-content/artifacts/7be125fa722503182ec4b6645552cbfc37c9ec66093f185e7ea2a6b8ada57151-file.png)

## TO BE

![Manage plan row matching the other transparent profile menu
rows](https://ampcode.com/user-content/artifacts/cf8b6fab9ff1fbec51f840e2926599d97b6ac75db6f54a3cb52a0ee315373d6f-file.png)

## Testing

- `pnpm exec vitest run
src/platform/workspace/components/CurrentUserPopoverWorkspace.test.ts`
(16/16 passed)
- `PLAYWRIGHT_LOCAL=1 PLAYWRIGHT_TEST_URL=http://localhost:5173 pnpm
exec playwright test
browser_tests/tests/currentUserPopoverCredits.spec.ts --project=cloud
--grep "plain full-width" --update-snapshots`
- `pnpm typecheck:browser`
- `pnpm typecheck`
- `pnpm exec oxfmt --check
browser_tests/tests/currentUserPopoverCredits.spec.ts
src/platform/workspace/components/CurrentUserPopoverWorkspace.vue`

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: github-actions <github-actions@github.com>

Author: 3 people

browser_tests/tests/currentUserPopoverCredits.spec.ts

@@ -8,6 +8,8 @@ import type {
 import type { WorkspaceTokenResponse } from '@/platform/workspace/stores/workspaceAuthStore'
 import type { operations } from '@/types/comfyRegistryTypes'
 import { comfyPageFixture } from '@e2e/fixtures/ComfyPage'
+import { APP_URL, setupCloudApp } from '@e2e/fixtures/utils/cloudAppSetup'
+import { workspace } from '@e2e/fixtures/utils/workspaceMocks'
 
 type CustomerBalanceResponse = NonNullable<
   operations['GetCustomerBalance']['responses']['200']['content']['application/json']
@@ -164,4 +166,36 @@ test.describe('Current user popover credits row', { tag: '@cloud' }, () => {
     const resubscribeRight = resubscribeBox!.x + resubscribeBox!.width
     expect(resubscribeRight).toBeLessThanOrEqual(popoverRight)
   })
+
+  test(
+    'renders Manage plan as a plain full-width menu row',
+    { tag: '@screenshot' },
+    async ({ page }) => {
+      test.setTimeout(60_000)
+      await setupCloudApp(page, {
+        workspace: workspace('personal', 'owner'),
+        features: { subscription_required: false }
+      })
+      await page.goto(APP_URL)
+      await page.waitForFunction(() => !!window.app?.extensionManager, null, {
+        timeout: 45_000
+      })
+      await page.getByRole('button', { name: 'Close dialog' }).click()
+      await expect(page.getByTestId('dialog-overlay')).toBeHidden()
+
+      await page.getByRole('button', { name: 'Current user' }).click()
+
+      const managePlan = page.getByRole('button', { name: 'Manage plan' })
+      await expect(managePlan).toBeVisible()
+      await expect(managePlan).toHaveScreenshot('manage-plan-menu-item.png')
+
+      await managePlan.focus()
+      await page.keyboard.press('Shift+Tab')
+      await page.keyboard.press('Tab')
+      await expect(managePlan).toBeFocused()
+      await expect(managePlan).toHaveScreenshot(
+        'manage-plan-menu-item-focused.png'
+      )
+    }
+  )
 })

browser_tests/tests/currentUserPopoverCredits.spec.ts-snapshots/manage-plan-menu-item-cloud-linux.png

@@ -153,7 +153,7 @@
     <button
       v-if="!accountActionsOnly && showManagePlan"
       type="button"
-      class="flex cursor-pointer items-center gap-2 px-4 py-2 hover:bg-secondary-background-hover"
+      class="flex w-full cursor-pointer appearance-none items-center gap-2 border-0 bg-transparent px-4 py-2 text-left hover:bg-secondary-background-hover focus-visible:bg-secondary-background-hover focus-visible:outline-none"
       data-testid="manage-plan-menu-item"
       @click="handleOpenPlanAndCreditsSettings"
     >