e2e(FR-2464): review and rewrite failing VFolder e2e tests (#6477)

Resolves #6415(FR-2464)

## Summary
- Fix TOML duplicate key parsing with `deduplicateTomlKeys()` utility
- Replace fragile CSS selectors with `navigateTo()` and `selectPropertyFilter()`
- Improve share/invitation flow with proper modal handling and visibility checks
- Add extended timeouts for `afterAll` cleanup hooks (delete-forever operations)
- Make `test.describe.serial` where tests share state (creation, sharing)
- Improve `deleteForeverAndVerifyFromTrash` flow with button enabled wait

## Test plan
- [ ] All VFolder E2E tests pass against test server
- [ ] VFolder CRUD lifecycle test passes end-to-end
- [ ] VFolder sharing test passes with proper cleanup

Author: ironAiken2

e2e/utils/classes/vfolder/FolderExplorerModal.ts

@@ -53,6 +53,9 @@ export class FolderExplorerModal {
       name: 'upload Upload',
     });
     await expect(uploadButton).toBeVisible({ timeout: 10000 });
+    // Give the modal toolbar a moment to settle so click() doesn't fail with
+    // "element is not stable" under heavy parallel load.
+    await this.page.waitForTimeout(300);
     return uploadButton;
   }
 
@@ -61,6 +64,7 @@ export class FolderExplorerModal {
       name: 'folder-add Create Folder',
     });
     await expect(createButton).toBeVisible();
+    await this.page.waitForTimeout(300);
     return createButton;
   }
 
@@ -138,7 +142,7 @@ export class FolderExplorerModal {
     await expect(
       this.modal.getByRole('cell').filter({ hasText: fileName }),
     ).toBeVisible({
-      timeout: 10000,
+      timeout: 30000,
     });
   }
 }