test(sql-editor): e2e coverage + delete jsdom test + merge Results.utils tests (Steps 5-6) (#48217)

## Summary

Steps 5 and 6 of the SQL editor test refactor plan (the final two
steps).

**Step 5** — extends `e2e/studio/features/sql-editor.spec.ts` (real
browser, zero mocks) with cases that need the real Monaco editor / full
app render:
- destructive-query warning modal: confirm actually re-runs the forced
query (previously only `Cancel` was exercised)
- debug button opens the AI Assistant with the query error pre-filled

Deletes `apps/studio/tests/components/SQLEditor/SQLEditor.test.tsx` —
its logic-level cases are now covered mock-free by the Step 4 hook
tests, and its integration cases by e2e. Deleting rather than narrowing
is the honest consequence of "no mocking": every remaining assertion it
could make in jsdom requires a Monaco mock.

**Step 6** — merges
`apps/studio/tests/components/SQLEditor/Results.utils.test.ts`
(`formatClipboardValue`/`formatCellValue`) into the colocated
`apps/studio/components/interfaces/SQLEditor/UtilityPanel/Results.utils.test.ts`
(`formatResults`/`convertResultsToMarkdown`/`convertResultsToJSON`/`getResultsHeaders`/`isLargeValue`/`convertResultsToCSV`)
— both tested disjoint exports of the same source file. Deletes the
`tests/` copy.

This is the last step in the plan.

## Test plan

- [x] `pnpm --filter studio typecheck` — no new errors in changed files
- [x] `npx prettier --check` on all changed files
- [x] Ran the new/changed e2e cases locally end-to-end against a live
local stack — both pass
- [x] `cd apps/studio && npx vitest run
components/interfaces/SQLEditor/UtilityPanel/Results.utils.test.ts` —
42/42 passing after the merge

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

* **Tests**
* Added end-to-end coverage for destructive SQL query warning modal flow
before forced execution.
* Added end-to-end coverage for the AI Assistant debug flow when SQL
execution fails.
* Expanded unit test coverage for SQL editor results formatting
utilities (clipboard and cell value formatting).
* Removed the prior SQLEditor unit test suite and the older
results-formatting unit tests.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

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

@@ -406,6 +406,84 @@ test.describe('SQL Editor', () => {
     }
   })
 
+  test('destructive query warning modal: confirm re-runs the forced query', async ({ ref }) => {
+    await expect(page.getByText('Loading...')).not.toBeVisible()
+    await page.locator('.view-lines').click()
+    await page.keyboard.press('ControlOrMeta+KeyA')
+    await page.keyboard.type(`drop table pw_sql_editor_confirm_dne_e2e;`)
+
+    // Track whether the SQL editor dispatches this specific query to pg-meta
+    let queryDispatched = false
+    const listener = (request: any) => {
+      if (
+        request.url().includes('query?key=') &&
+        request.method() === 'POST' &&
+        request.postData()?.includes('drop table pw_sql_editor_confirm_dne_e2e')
+      ) {
+        queryDispatched = true
+      }
+    }
+    page.on('request', listener)
+
+    await page.getByTestId('sql-run-button').click()
+
+    // Destructive query -> confirmation modal, and no query is sent yet.
+    await expect(page.getByRole('heading', { name: 'Potential issue detected' })).toBeVisible()
+    expect(queryDispatched).toBe(false)
+
+    // Confirming forces the (same) destructive query to actually run.
+    const sqlMutationPromise = waitForApiResponse(page, 'pg-meta', ref, 'query?key=', {
+      method: 'POST',
+    })
+    await page.getByRole('button', { name: 'Run query' }).click()
+    await sqlMutationPromise
+    expect(queryDispatched).toBe(true)
+
+    page.removeListener('request', listener)
+
+    // clear SQL snippet
+    if (!isCLI()) {
+      await deleteSqlSnippet(page, ref, newSqlSnippetName)
+    } else {
+      await page.reload()
+    }
+  })
+
+  test('debug button opens the AI Assistant with the query error pre-filled', async ({ ref }) => {
+    await expect(page.getByText('Loading...')).not.toBeVisible()
+    await page.locator('.view-lines').click()
+    await page.keyboard.press('ControlOrMeta+KeyA')
+    await page.keyboard.type(`select * from pw_sql_editor_missing_table_e2e;`)
+
+    const sqlMutationPromise = waitForApiResponse(page, 'pg-meta', ref, 'query?key=', {
+      method: 'POST',
+    })
+    await page.getByTestId('sql-run-button').click()
+    await sqlMutationPromise
+
+    const debugButton = page.getByRole('button', { name: 'Debug with Assistant' })
+    await expect(debugButton, 'Debug button should appear once the query errors').toBeVisible()
+    await debugButton.click()
+
+    await expect(
+      page.getByRole('button', { name: 'Close Assistant' }),
+      'AI Assistant panel should open'
+    ).toBeVisible()
+    await expect(
+      page.getByRole('button', { name: 'Debug SQL snippet' }),
+      'Assistant chat should be pre-named for the debug flow'
+    ).toBeVisible()
+
+    await page.getByRole('button', { name: 'Close Assistant' }).click()
+
+    // clear SQL snippet
+    if (!isCLI()) {
+      await deleteSqlSnippet(page, ref, newSqlSnippetName)
+    } else {
+      await page.reload()
+    }
+  })
+
   test('should not show warning modal for safe alter database statement', async ({ ref }) => {
     await expect(page.getByText('Loading...')).not.toBeVisible()
     await page.locator('.view-lines').click()