Application Load Balancer: activity and metrics

[mattdjenkinson]

We've given Application Load Balancers a proper activity timeline and a new home for their metrics.

Highlights:

• Readable Activity – The timeline now says what actually happened — created, hostname changed, backend updated, basic auth turned on — instead of raw Kubernetes update events.
• Fewer False Alarms – Certificate and programming hiccups show up as a single failure line, not a flood of pending noise.
• Full Picture – Traffic protection, DNS, and basic auth changes now show up on the load balancer's own activity tab and link straight back to it.
• Dedicated Metrics Tab – Traffic, latency, geography, and WAF charts moved off the Overview page onto their own tab, with time range, region, and refresh controls that stick as you scroll.
• Live Points of Presence – The Active POPs globe now pulls from our Locations catalog instead of a hardcoded list, so it stays accurate as we add locations, and shows up right after a load balancer is created instead of waiting on a refresh.