fix: resolve i18n no-restricted-imports lint warnings (#8704)

## Summary

Fix all i18n `no-restricted-imports` lint warnings and upgrade rules
from `warn` to `error`.

## Changes

- **What**: Migrate Vue components from `import { t/d } from '@/i18n'`
to `const { t } = useI18n()`. Migrate non-component `.ts` files from
`useI18n()` to `import { t/d } from '@/i18n'`. Allow `st` import from
`@/i18n` in Vue components (it wraps `te`/`t` for safe fallback
translation). Remove `@deprecated` tag from `i18n.ts` global exports
(still used by `st` and non-component code). Upgrade both lint rules
from `warn` to `error`.

## Review Focus

- The `st` helper is intentionally excluded from the Vue component
restriction since it provides safe fallback translation needed for
custom node definitions.

Fixes #8701

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8704-fix-resolve-i18n-no-restricted-imports-lint-warnings-2ff6d73d365081ae84d8eb0dfef24323)
by [Unito](https://www.unito.io)

---------

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

src/components/topbar/CloudBadge.vue

@@ -10,8 +10,8 @@
 
 <script setup lang="ts">
 import { computed } from 'vue'
+import { useI18n } from 'vue-i18n'
 
-import { t } from '@/i18n'
 import type { TopbarBadge as TopbarBadgeType } from '@/types/comfy'
 
 import TopbarBadge from './TopbarBadge.vue'
@@ -31,6 +31,8 @@ withDefaults(
   }
 )
 
+const { t } = useI18n()
+
 const cloudBadge = computed<TopbarBadgeType>(() => ({
   label: t('g.beta'),
   text: 'Comfy Cloud'

src/components/topbar/LoginButton.vue

@@ -37,17 +37,18 @@
 import Popover from 'primevue/popover'
 import type { HTMLAttributes } from 'vue'
 import { ref } from 'vue'
+import { useI18n } from 'vue-i18n'
 
 import Button from '@/components/ui/button/Button.vue'
 import { useCurrentUser } from '@/composables/auth/useCurrentUser'
 import { useExternalLink } from '@/composables/useExternalLink'
-import { t } from '@/i18n'
 import { cn } from '@/utils/tailwindUtil'
 
 const { class: className } = defineProps<{
   class?: HTMLAttributes['class']
 }>()
 
+const { t } = useI18n()
 const { isLoggedIn, handleSignIn } = useCurrentUser()
 const { buildDocsUrl } = useExternalLink()
 const apiNodesOverviewUrl = buildDocsUrl(