RosePlugs: add Nexus plugin metadata fetch/cache

plugins/rose-plugs/src/lib/nexusApi.ts

@@ -0,0 +1,50 @@
+export interface NexusPlugin {
+    id: string;
+    name: string;
+    description: string;
+    authors: string[];
+    category: string;
+    status: string;
+    accent: string;
+    tagline: string;
+    note: string;
+    howItWorks: string;
+    features: string[];
+    commands: string[];
+    limitations: string;
+    pageUrl: string;
+    installUrl: string;
+    sourceUrl: string;
+    issueUrl: string;
+}
+
+const NEXUS_URL = "https://rp.jarviscli.dev/plugins-data.json";
+
+let cache: NexusPlugin[] | null = null;
+let inflight: Promise<NexusPlugin[]> | null = null;
+
+export async function fetchNexusPlugins(force = false): Promise<NexusPlugin[]> {
+    if (!force && cache) return cache;
+    if (!force && inflight) return inflight;
+
+    inflight = fetch(NEXUS_URL)
+        .then((res) => {
+            if (!res.ok) throw new Error(`Nexus fetch failed: ${res.status}`);
+            return res.json();
+        })
+        .then((data: NexusPlugin[]) => {
+            cache = data;
+            inflight = null;
+            return data;
+        })
+        .catch((e) => {
+            inflight = null;
+            throw e;
+        });
+
+    return inflight;
+}
+
+export function clearNexusCache(): void {
+    cache = null;
+}