fix(header): sync ESI CSS variables for the new header states

[mcstover]

Restores the ESI CSS-variable personalization that KvWwwHeaderBasic lost when it shipped. The variables were already emitted and already bridged; the hooks that read them were missing, so both ends were inert.

• The bridge only applied while user data was loading, so --basket-display never reached the header during a basket-only load.
• userAvatarData emitted user-avatar unconditionally, leaving the real-avatar element shown with an empty image whenever there was nothing to paint. It now emits the url only when it will be shown, and hides that element otherwise so the avatar icon carries the state.
• Adds the logged-out signal (user-loading-display) that the logged-in cluster hook needs.

Scope of effect

useCDNCaching is route meta and only /ui-site-map sets it (src/router/routes.js:696-701), so the header binds display to these variables on that route alone. Live today: the basket hook and the cluster hook.

The user-avatar polarity fix has no live consumer yet. avatarMode cannot reach esi until KvWwwHeaderBasic exposes useEsiAvatar (CIT-5084), and MyKivaButton — the other component that reads these variables, directly under the --ui-data- prefix — only renders on minimal and corporate pages, which are never CDN-cached, so its variable branch is unreachable. That part of the change is groundwork for CIT-5085 rather than a visible fix.

One intended behaviour change where the hooks are live: on a stale logged-in-filled cached shell served to a logged-out visitor, the cluster is now suppressed pre-hydration. The visitor links are v-if-driven and stay hidden (design decision D4), so that visitor briefly sees neither the cluster nor a Log in link, where before they saw placeholder chrome.

Verifying

ESI resolves locally, not only at Fastly: server/vue-render.js:24-26 runs a nodesi processor over the rendered HTML when config.server.simulateCDN is set, and index.html:5 carries the /esi-ui/head include. Under that flag cdnNotedLoggedIn comes from the kvls login-sync cookie rather than the Fastly header (server/vue-middleware.js:101-105), so both loading states are reachable locally.

With a simulateCDN: true config, on /ui-site-map:

• logged out with no kvbskt cookie → no basket link at any point;
• kvls set to anything other than o while not actually logged in → the logged-in cluster stays suppressed.

Logged-in user state confirmed loading correctly.

Covers CIT-5069 items 1, 2 and 4, and CIT-5071 item 3. The remaining items need kv-ui-elements changes and are tracked in CIT-5084 and CIT-5085.

https://kiva.atlassian.net/browse/CIT-5069
https://kiva.atlassian.net/browse/CIT-5071

[emuvente]

Great fix! The description claims that this doesn't change local behavior because "local dev has no ESI", but that's not true. We process ESI locally:

ui/server/vue-render.js

Line 51 in 131e350

const finalHtml = processESITags ? await esi.process(html, {

. Please verify the behavior locally and not just in a Fastly-fronted environment.

[mcstover]

@emuvente I had already verified the work locally and have once more. Also had claude update the description

[kiva-robot]

🎉 This PR is included in version 3.91.0-rc.1 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀

[kiva-robot]

🎉 This PR is included in version 3.91.0 🎉

The release is available on GitHub release

Your semantic-release bot 📦🚀