Button, Input, Select, Badge, SeverityBadge, Table, Card, Modal,
Tooltip, Tabs, Skeleton, EmptyState -- a shared library so pages stop
hand-rolling markup per page (web/src/lib/components/ui, barrel export
in index.ts). Modal and CommandPalette are built on native <dialog>
for a real focus trap, Escape-to-close, and top-layer stacking instead
of hand-rolling those. Tabs uses roving tabindex with arrow-key nav.
NavSidebar replaces the old top-nav with a persistent sidebar
(Search/Dashboards/Alerts/Data Sources/Settings), a live tenant
indicator (api.ts's new getCurrentSession(), a client for the
already-existing POST /internal/authorize -- zero new backend surface),
theme/density quick-toggles, and a command-palette hint. Collapses to
an off-canvas drawer under 860px. CommandPalette (Cmd/Ctrl+K) indexes
the five static destinations plus live-fetched dashboards/alert rules.
Data Sources is a new, honestly-scoped placeholder page (one data
source per tenant today, no UI needed yet). Settings and Select-tenant
are re-tokened onto the new component library. +layout.svelte's content
wrapper is a plain <div>, not a second <main> -- every page already
renders its own top-level <main>.
