Refactor frontend pages and config components into single-component files for Task 13

frontend/src/components/config/CommandField.tsx

@@ -0,0 +1,21 @@
+import { Field, Textarea } from "@fluentui/react-components";
+
+interface CommandFieldProps {
+  label: string;
+  value: string;
+  onChange: (v: string) => void;
+}
+
+export function CommandField({ label, value, onChange }: CommandFieldProps): React.JSX.Element {
+  return (
+    <Field label={label}>
+      <Textarea
+        value={value}
+        onChange={(_e, d) => { onChange(d.value); }}
+        rows={value.split("\n").length + 1}
+        style={{ fontFamily: "monospace", width: "100%" }}
+        placeholder={`${label} command(s)`}
+      />
+    </Field>
+  );
+}