admin: live ring capacity is injectable, eviction test no longer timing-bound

admin/src/features/activity/LiveActivity.tsx

@@ -276,8 +276,19 @@ function LiveDetail({ row, origin, onClose }: { row: StreamedRow; origin: Activi
 	);
 }
 
-export default function LiveActivity({ origin }: { origin: ActivitySearch }) {
-	const live = useLiveQueries();
+/**
+ * `capacity` is the ring size, a parameter only so a test can provoke an
+ * eviction with a handful of rows rather than 500 frames through React state.
+ * The route renders this without it, so the app is always the 500-row ring.
+ */
+export default function LiveActivity({
+	origin,
+	capacity = RING_CAPACITY,
+}: {
+	origin: ActivitySearch;
+	capacity?: number;
+}) {
+	const live = useLiveQueries({ capacity });
 	const clientNames = useClientNames();
 	const [selected, setSelected] = useState<StreamedRow | null>(null);
 	const trigger = useRef<HTMLButtonElement | null>(null);
@@ -312,8 +323,7 @@ export default function LiveActivity({ origin }: { origin: ActivitySearch }) {
 
 			{live.frozen && (
 				<p {...stylex.props(styles.note)} role="status">
-					Display frozen — new queries keep buffering ({live.liveCount} in buffer, newest {RING_CAPACITY}{" "}
-					kept).
+					Display frozen — new queries keep buffering ({live.liveCount} in buffer, newest {capacity} kept).
 				</p>
 			)}
 
@@ -413,7 +423,7 @@ export default function LiveActivity({ origin }: { origin: ActivitySearch }) {
 					</div>
 					<p {...stylex.props(styles.footnote)}>
 						Showing {live.rows.length} {live.rows.length === 1 ? "query" : "queries"} (newest first, last{" "}
-						{RING_CAPACITY} kept).
+						{capacity} kept).
 					</p>
 				</>
 			)}