fix(tests): update reset button selector for new use-kbd

The use-kbd update changed the reset button class from `kbd-reset-btn`
to `kbd-footer-btn`. Use text-based selector instead for robustness.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: ryan-williams

www/test/e2e/hotkey-editing.spec.ts

@@ -459,8 +459,8 @@ test.describe('Hotkey Editing', () => {
     // Verify we now have both T and Z
     await expect(leftCell.locator('kbd', { hasText: 'T' })).toBeVisible()
 
-    // Click Reset button
-    await page.locator('.kbd-modal .kbd-reset-btn').click()
+    // Click Reset button (in footer)
+    await page.locator('.kbd-modal button:has-text("Reset")').click()
     await page.waitForTimeout(300)
 
     // Verify Z is gone and only T remains