We currently rely on the full Codex library module for the main WikiLambda app, which can be quite a bit of dead-weight code we don't use (and more so each month as they add new features that we're not yet using). For the global language selector, we already rely on a slim version

• Audit all our Codex components and determine which we're using.
• Replace the dependency in extension.json for the app with a manifest, like we already do for the global language selector.
• Change our jest test code to load specific components, not the whole library (so we notice in CI if we're using a component we don't rely on in the manifest).
• Check that this actually reduces bytes sent and the additional CPU load / cache misses are reasonable.