feat(web): Pressing Plant component library + describeJob

design.css component classes (masthead, contents nav, tiles, dept header,
job row + severity stripe, status chip, progress bar, pressed list, buttons,
fields). Presentational _ui components. describeJob maps worker Job.state to
literal labels + severity kind + stepped progress (unit-tested).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

web/src/app/_ui/status-chip.tsx

@@ -0,0 +1,5 @@
+import type { Kind } from "./status";
+
+export function StatusChip({ kind, label }: { kind: Kind; label: string }) {
+  return <span className={`chip ${kind}`}>{label}</span>;
+}