fix: protect csv import (#47040)

## TL;DR 
fixes protected schema empty tables still exposing CSV import actions in
table editor...
## ref: 
- closes https://github.com/supabase/supabase/issues/41358
- supersedes: https://github.com/supabase/supabase/pull/41362
<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Bug Fixes**
* Updated the table empty state so CSV import actions are shown only
when the table is allowed to accept imports, and are hidden for
protected cases (including foreign-table scenarios).

* **Tests**
* Added an end-to-end test confirming that empty tables in protected
schemas do not expose the “Import data from CSV” button or the
drag-and-drop CSV hint.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

e2e/studio/features/table-editor.spec.ts

@@ -1,7 +1,5 @@
 import fs from 'fs'
 import path from 'path'
-import { expect, Page } from '@playwright/test'
-
 import { env } from '../env.config.js'
 import { expectClipboardValue } from '../utils/clipboard.js'
 import { dropTable, query } from '../utils/db/index.js'
@@ -16,6 +14,7 @@ import {
   waitForGridDataToLoad,
   waitForTableToLoad,
 } from '../utils/wait-for-response.js'
+import { expect, Page } from '@playwright/test'
 
 const deleteTable = async (page: Page, ref: string, tableName: string) => {
   const viewLocator = page.getByLabel(`View ${tableName}`)
@@ -155,6 +154,37 @@ testRunner('table editor', () => {
     await expect(page.getByLabel(`View ${authTableMfa}`)).toBeVisible()
   })
 
+  test('protected schema empty tables do not expose CSV import actions', async ({ page, ref }) => {
+    const emptyAuthTables = await query<{ relname: string }>(`
+      select relname
+      from pg_stat_user_tables
+      where schemaname = 'auth'
+        and n_live_tup = 0
+        and relname <> 'schema_migrations'
+      order by relname
+      limit 1;
+    `)
+    test.skip(emptyAuthTables.length === 0, 'Requires an empty auth table in the test dataset')
+    const [{ relname: tableName }] = emptyAuthTables
+
+    await page.goto(toUrl(`/project/${ref}/editor?schema=public`))
+
+    await page.getByTestId('schema-selector').click()
+    await page.getByPlaceholder('Find schema...').fill('auth')
+
+    const tableLoadPromise = waitForTableToLoad(page, ref, 'auth')
+    await page.getByRole('option', { name: 'auth' }).click()
+    await tableLoadPromise
+
+    await expect(page.getByRole('button', { name: `View ${tableName}`, exact: true })).toBeVisible()
+    await page.getByRole('button', { name: `View ${tableName}`, exact: true }).click()
+    await page.waitForURL(/\/editor\/\d+\?schema=auth$/)
+
+    await expect(page.getByText('This table is empty')).toBeVisible()
+    await expect(page.getByRole('button', { name: 'Import data from CSV' })).not.toBeVisible()
+    await expect(page.getByText('or drag and drop a CSV file here')).not.toBeVisible()
+  })
+
   test('should show rls accordingly', async ({ page, ref }) => {
     const tableNameRlsEnabled = 'pw_table_rls_enabled'
     const tableNameRlsDisabled = 'pw_table_rls_disabled'