Each polling page repeated its own fetch-and-set code on a fixed timer,
so a slow answer could be overtaken by the next tick, an older response
could overwrite a newer one, and nothing aborted a request when the page
went away.
usePolled skips a tick while a request is in flight, aborts on unmount
or refresh, ignores answers from dropped requests, and keeps the last
good data under an error. The alerts, hives, agents, schedules, builds,
review runs and broadcast pages and the subagent list use it.
/builds lists the builder's recent builds newest first, one card each with how
it ended, and opens a failed build's nix tail. /builds?run=<id> opens that
build's card and scrolls to it. The swarm-builder commit status now links
there instead of to the raw JSON record.
