fix: remove incorrect tooltip on remaining credit balance (#7383)

## Summary
Removed incorrect tooltip displayed on the remaining credit balance in
the subscription panel.

## Changes
- **What**: Removed unused `refreshTooltip` destructure and i18n
translation key
- **Breaking**: None

Fixes #6694

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-7383-fix-remove-incorrect-tooltip-on-remaining-credit-balance-2c66d73d3650814eaee0f3c9006b7bd6)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Claude <noreply@anthropic.com>

tests-ui/tests/platform/cloud/subscription/components/SubscriptionPanel.test.ts

@@ -42,7 +42,6 @@ const mockCreditsData = {
 
 const mockActionsData = {
   isLoadingSupport: false,
-  refreshTooltip: 'Refreshes on 2024-12-31',
   handleAddApiCredits: vi.fn(),
   handleMessageSupport: vi.fn(),
   handleRefresh: vi.fn(),

tests-ui/tests/platform/cloud/subscription/composables/useSubscriptionActions.test.ts

@@ -7,23 +7,6 @@ const mockFetchBalance = vi.fn()
 const mockFetchStatus = vi.fn()
 const mockShowTopUpCreditsDialog = vi.fn()
 const mockExecute = vi.fn()
-const mockT = vi.fn((key: string, values?: any) => {
-  if (key === 'subscription.nextBillingCycle') return 'next billing cycle'
-  if (key === 'subscription.refreshesOn') {
-    return `Refreshes to $${values?.monthlyCreditBonusUsd} on ${values?.date}`
-  }
-  return key
-})
-
-vi.mock('vue-i18n', async (importOriginal) => {
-  const actual = await importOriginal<typeof import('vue-i18n')>()
-  return {
-    ...actual,
-    useI18n: () => ({
-      t: mockT
-    })
-  }
-})
 
 vi.mock('@/composables/auth/useFirebaseAuthActions', () => ({
   useFirebaseAuthActions: () => ({
@@ -31,12 +14,9 @@ vi.mock('@/composables/auth/useFirebaseAuthActions', () => ({
   })
 }))
 
-const mockFormattedRenewalDate = { value: '2024-12-31' }
-
 vi.mock('@/platform/cloud/subscription/composables/useSubscription', () => ({
   useSubscription: () => ({
-    fetchStatus: mockFetchStatus,
-    formattedRenewalDate: mockFormattedRenewalDate
+    fetchStatus: mockFetchStatus
   })
 }))
 
@@ -62,23 +42,6 @@ Object.defineProperty(window, 'open', {
 describe('useSubscriptionActions', () => {
   beforeEach(() => {
     vi.clearAllMocks()
-    mockFormattedRenewalDate.value = '2024-12-31'
-  })
-
-  describe('refreshTooltip', () => {
-    it('should format tooltip with renewal date', () => {
-      const { refreshTooltip } = useSubscriptionActions()
-      expect(refreshTooltip.value).toBe('Refreshes to $10 on 2024-12-31')
-    })
-
-    it('should use fallback text when no renewal date', () => {
-      mockFormattedRenewalDate.value = ''
-      const { refreshTooltip } = useSubscriptionActions()
-      expect(refreshTooltip.value).toBe(
-        'Refreshes to $10 on next billing cycle'
-      )
-      expect(mockT).toHaveBeenCalledWith('subscription.nextBillingCycle')
-    })
   })
 
   describe('handleAddApiCredits', () => {