Add js web stuff to landing page + documentation

go/jsruntime/uikit/RemoteUpdateFlash.tsx

@@ -0,0 +1,38 @@
+import { createSignal, Show } from "solid-js";
+
+/**
+ * Creates a trigger/signal pair for showing a brief "remote update" flash.
+ * Call `fire()` when a remote WebSocket update arrives; `visible()` goes
+ * true for `durationMs` then auto-clears.
+ */
+export function createRemoteFlash(durationMs = 3000) {
+    const [visible, setVisible] = createSignal(false);
+    let timer: ReturnType<typeof setTimeout> | null = null;
+
+    const fire = () => {
+        setVisible(true);
+        if (timer) clearTimeout(timer);
+        timer = setTimeout(() => {
+            setVisible(false);
+            timer = null;
+        }, durationMs);
+    };
+
+    return { visible, fire };
+}
+
+interface RemoteUpdateFlashProps {
+    when: boolean;
+}
+
+/**
+ * A small pill that briefly shows "Updated".
+ */
+export function RemoteUpdateFlash(props: RemoteUpdateFlashProps) {
+    return <Show when={props.when}>
+        <div class="remote-update-flash inline-flex items-center gap-1 rounded-full bg-emerald-100 dark:bg-emerald-950/50 border border-emerald-300 dark:border-emerald-800 px-2 py-0.5 text-[10px] font-semibold uppercase tracking-widest text-emerald-700 dark:text-emerald-400">
+            <svg viewBox="0 0 12 12" class="w-2.5 h-2.5 fill-current"><circle cx="6" cy="6" r="6"/></svg>
+            Updated
+        </div>
+    </Show>;
+}