feat: enforce i18n import conventions via ESLint (#8701)

## Summary

Enforce i18n import conventions via ESLint: Vue components must use
`useI18n()`, non-composable `.ts` files must use the global `t` from
`@/i18n`.

## Changes

- **What**: Two new `no-restricted-imports` rules in `eslint.config.ts`
(both `warn` severity for incremental migration). Removed the disabled
`@/i18n--to-enable` placeholder from `.oxlintrc.json`.
- `.vue` files: disallow importing `t`/`d`/`st`/`te` from `@/i18n` (37
existing violations to migrate)
- Non-composable `.ts` files: disallow importing `useI18n` from
`vue-i18n` (2 existing violations)
- Composable `use*.ts`, test files, and `src/i18n.ts` are excluded from
Rule 2

## Review Focus

- The rules are placed after `oxlint.buildFromOxlintConfigFile()` to
re-enable ESLint's `no-restricted-imports` for these specific file
scopes without conflicting with oxlint's base rule (which handles
PrimeVue deprecations).
- `warn` severity chosen so CI is not blocked while existing violations
are migrated.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-8701-feat-enforce-i18n-import-conventions-via-ESLint-2ff6d73d36508123b6f9edf2693fb5e0)
by [Unito](https://www.unito.io)

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>

.oxlintrc.json

@@ -60,11 +60,6 @@
           {
             "name": "primevue/sidebar",
             "message": "Sidebar is deprecated in PrimeVue 4+. Use Drawer instead: import Drawer from 'primevue/drawer'"
-          },
-          {
-            "name": "@/i18n--to-enable",
-            "importNames": ["st", "t", "te", "d"],
-            "message": "Don't import `@/i18n` directly, prefer `useI18n()`"
           }
         ]
       }

eslint.config.ts

@@ -279,5 +279,46 @@ export default defineConfig([
       'import-x/no-duplicates': 'off',
       'import-x/consistent-type-specifier-style': 'off'
     }
+  },
+
+  // i18n import enforcement
+  // Vue components must use the useI18n() composable, not the global t/d/st/te
+  {
+    files: ['**/*.vue'],
+    rules: {
+      'no-restricted-imports': [
+        'warn',
+        {
+          paths: [
+            {
+              name: '@/i18n',
+              importNames: ['t', 'd', 'st', 'te'],
+              message:
+                "In Vue components, use `const { t } = useI18n()` instead of importing from '@/i18n'."
+            }
+          ]
+        }
+      ]
+    }
+  },
+  // Non-composable .ts files must use the global t/d/st/te, not useI18n()
+  {
+    files: ['**/*.ts'],
+    ignores: ['**/use[A-Z]*.ts', '**/*.test.ts', 'src/i18n.ts'],
+    rules: {
+      'no-restricted-imports': [
+        'warn',
+        {
+          paths: [
+            {
+              name: 'vue-i18n',
+              importNames: ['useI18n'],
+              message:
+                "useI18n() requires Vue setup context. Use `import { t } from '@/i18n'` instead."
+            }
+          ]
+        }
+      ]
+    }
   }
 ])