Fix deprecated React/Apollo Client console warnings

[Copilot]

Multiple console warnings/errors from deprecated or removed APIs: findDOMNode deprecation via reactstrap's Collapse/Navbar, Apollo Client 3.14+ uri shorthand removal, React Router v7 dropping forceRefresh, and unreachable dead code with invalid HTML tags in Donate.js.

Changes

App.js

• Apollo Client: Replace deprecated uri shorthand with explicit HttpLink. Apollo Client 3.14+ emits console.warn when uri is passed directly to ApolloClient:

  // Before
  new ApolloClient({ uri: '/graphql', cache: new InMemoryCache() })
  
  // After
  new ApolloClient({ link: new HttpLink({ uri: '/graphql' }), cache: new InMemoryCache() })

• ApolloClient instantiation: Moved from render() to constructor — was creating a new instance (and re-emitting warnings) on every render
• forceRefresh prop: Removed from <BrowserRouter> — prop was dropped in React Router v7; passing it generates unknown-prop warnings

Donate.js

• Removed unreachable second return block containing invalid HTML elements (<h8>, <h7>, <h11>) that would produce browser console errors

[Copilot]

Pull request overview

This PR aims to eliminate frontend console warnings caused by deprecated/removed APIs across React Router, Apollo Client, and invalid/unreachable React markup.

Changes:

• Updates Apollo Client setup to use an explicit HttpLink and instantiates the client once in App’s constructor.
• Removes the deprecated forceRefresh prop from the router configuration.
• Deletes unreachable JSX in Donate.js that included invalid HTML heading tags.
• Adds @testing-library/dom to the frontend dependency set (with corresponding lockfile updates).

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 2 comments.

File	Description
frontend/src/App.js	Switches Apollo Client creation to HttpLink and makes it a single instance; removes forceRefresh usage.
frontend/src/components/Donate.js	Removes unreachable duplicate return block containing invalid HTML tags.
frontend/package.json	Adds @testing-library/dom to dependencies.
frontend/package-lock.json	Updates lockfile to include new dependency and includes additional dependency resolution/version changes.

Files not reviewed (1)

• frontend/package-lock.json: Language not supported

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[conorheffron]

@copilot resolve the merge conflicts in this pull request

[conorheffron]

@copilot resolve the merge conflicts in this pull request

[Copilot]

@copilot resolve the merge conflicts in this pull request

Resolved the merge conflicts and pushed the merge commit in f6db9a8.

[Copilot]

@copilot resolve the merge conflicts in this pull request

Resolved in f6db9a8. The branch already contains the current main, so there are no merge conflicts left on this PR; GitHub is only showing checks running/blocked rather than a conflict state.