Kura remote cache no longer uses Cloudflare load balancing and returns 503 on empty endpoints

Kura remote caching no longer uses Cloudflare load balancing in Tuist’s managed production and regional deployments. The controller now skips Cloudflare LB credential wiring, and the cache endpoint API returns a 503 when Kura cannot resolve a valid endpoint instead of handing clients an empty URL. This removes the failure mode where Cloudflare origin quota exhaustion could break remote cache connectivity. Also, Cloudflare API errors are now surfaced with more detail, and origin-limit responses are classified as degraded reconciliation so workloads can still converge if load balancing is ever re-enabled.