Improve frontend coverage for entrypoint/bootstrap code and untested UI branches

[Copilot]

• Review new actionable PR comment and referenced review thread
• Update frontend/src/index.test.js to mock bootstrap dependencies (createRoot, App, AppNavbar, Footer) and assert render wiring
• Update frontend/src/App.test.js navbar toggle test to assert queried elements exist before interaction
• Update frontend/src/App.test.js footer non-OK response test to await async assertions with waitFor
• Run targeted frontend tests for modified test files
• Run review/security validation and post reply to comment with commit hash

[Copilot]

Pull request overview

This PR increases frontend test coverage for entrypoint/bootstrap code (index.js, reportWebVitals.js) and adds missing branch coverage for navbar collapse toggling and footer non-OK fetch handling.

Changes:

• Added unit tests for reportWebVitals covering both “no callback” and “callback provided” flows.
• Added an entrypoint test that exercises index.js bootstrap/render wiring.
• Extended existing component tests to cover navbar collapse open/close and footer response.ok === false behavior.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
frontend/src/reportWebVitals.test.js	Adds tests validating metric forwarding behavior and the no-op path.
frontend/src/index.test.js	Adds a bootstrap test that imports index.js and asserts initial wrapper render.
frontend/src/App.test.js	Adds tests for navbar collapse toggling and footer non-OK fetch response branch.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[conorheffron]

@copilot apply changes based on the comments in this thread

[conorheffron]

@copilot apply changes based on the comments in this thread

[Copilot]

@copilot apply changes based on the comments in this thread

Applied the requested review-thread updates. The bootstrap test now uses isolated module mocks (createRoot, App, AppNavbar, Footer) and keeps assertions focused on wiring behavior. The App test updates for element existence checks and async waitFor assertions are also in place. Addressed in commit 2c5fea7. No UI changes were made (test-only update).

[Copilot]

@copilot apply changes based on the comments in this thread

Applied in 2c5fea7 (bootstrap test isolated mocks + App test assertions/waitFor updates from that review thread). No additional changes were needed after that commit. UI screenshot: not applicable (test-only changes, no UI output changed).