Remove flakiness and re-enable test 11 (tests/11_collab_test.js)

[BentleyJOakes]

Test 11 (tests/11_collab_test.js) is currently skipped due to flakiness impacting collaborative test operations:

• The test is currently disabled with @disabled: true
• This test covers collaboration workflows, window handling, and link/element operations.

Task:

• Diagnose and resolve the instability causing test flakiness.
• Re-enable test 11 by removing the @disabled flag in the file.
• Confirm robust operation for CI and local environments.

Relevant code snippets:
tests/11_collab_test.js

// TODO: temporarily disable this test for CI and local runs; re-enable after fixing flakiness
module.exports = {
    '@disabled': true,
    ...
}

Typical operations involved:

• Multi-window handling (tab_a, tab_b, tab_c)
• Creation and linking of elements
• Syntax switching and client disconnects

Check for timing issues, async handling, and environmental dependencies that may impact reliability.

---

Labels: Test/CI/CD, bug
Issue type: Bug