Scheduled-task browsing/editing already lives on each server's detail
page (ServerDetail.tsx), so the overview page's filters, task-group
listing, and add/edit-task form were pure duplication -- the only
things it needs to do are list servers (as clickable cards) and let
an admin register new ones / issue or rotate agent tokens.
Renamed ServersTasks.tsx -> Servers.tsx to match its new, narrower
scope; updated the nav label, route, and ServerDetail's back-link
text from "Servers & Tasks" to "Servers" accordingly. No server-side
or API changes -- this only removes now-redundant frontend code.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>