feat: add GroupMetadataRenderer for NIP-29 group metadata (kind 39000)

Render kind 39000 events with group name, picture, description, and
an "Open Chat" link that opens the NIP-29 group in the chat viewer.

src/components/nostr/kinds/GroupMetadataRenderer.tsx

@@ -0,0 +1,91 @@
+import type { NostrEvent } from "@/types/nostr";
+import { getTagValue } from "applesauce-core/helpers";
+import { getSeenRelays } from "applesauce-core/helpers/relays";
+import { BaseEventContainer, ClickableEventTitle } from "./BaseEventRenderer";
+import { useGrimoire } from "@/core/state";
+import { MessageSquare } from "lucide-react";
+
+interface GroupMetadataRendererProps {
+  event: NostrEvent;
+}
+
+/**
+ * Renderer for NIP-29 Group Metadata events (kind 39000)
+ * Displays group info and links to chat
+ */
+export function GroupMetadataRenderer({ event }: GroupMetadataRendererProps) {
+  const { addWindow } = useGrimoire();
+
+  // Extract group metadata
+  const groupId = getTagValue(event, "d") || "";
+  const name = getTagValue(event, "name") || groupId;
+  const about = getTagValue(event, "about");
+  const picture = getTagValue(event, "picture");
+
+  // Get relay URL from where we saw this event
+  const seenRelaysSet = getSeenRelays(event);
+  const relayUrl = seenRelaysSet?.values().next().value;
+
+  const handleOpenChat = () => {
+    if (!relayUrl) return;
+
+    addWindow("chat", {
+      protocol: "nip-29",
+      identifier: {
+        type: "group",
+        value: groupId,
+        relays: [relayUrl],
+      },
+    });
+  };
+
+  const canOpenChat = !!relayUrl && !!groupId;
+
+  return (
+    <BaseEventContainer event={event}>
+      <div className="flex gap-3">
+        {/* Group Picture */}
+        <div
+          className={canOpenChat ? "cursor-crosshair" : ""}
+          onClick={canOpenChat ? handleOpenChat : undefined}
+        >
+          {picture ? (
+            <img
+              src={picture}
+              alt={name}
+              className="size-12 rounded-lg object-cover flex-shrink-0"
+            />
+          ) : (
+            <div className="size-12 rounded-lg bg-muted flex items-center justify-center flex-shrink-0">
+              <MessageSquare className="size-6 text-muted-foreground" />
+            </div>
+          )}
+        </div>
+
+        {/* Group Info */}
+        <div className="flex flex-col gap-1 min-w-0 flex-1">
+          <ClickableEventTitle event={event} className="font-semibold">
+            {name}
+          </ClickableEventTitle>
+
+          {about && (
+            <p className="text-xs text-muted-foreground line-clamp-2">
+              {about}
+            </p>
+          )}
+
+          {/* Open Chat Link */}
+          {canOpenChat && (
+            <button
+              onClick={handleOpenChat}
+              className="text-xs text-primary hover:underline flex items-center gap-1 w-fit mt-1"
+            >
+              <MessageSquare className="size-3" />
+              Open Chat
+            </button>
+          )}
+        </div>
+      </div>
+    </BaseEventContainer>
+  );
+}

src/components/nostr/kinds/index.tsx

@@ -61,6 +61,7 @@ import { ZapstoreAppSetRenderer } from "./ZapstoreAppSetRenderer";
 import { ZapstoreAppSetDetailRenderer } from "./ZapstoreAppSetDetailRenderer";
 import { ZapstoreReleaseRenderer } from "./ZapstoreReleaseRenderer";
 import { ZapstoreReleaseDetailRenderer } from "./ZapstoreReleaseDetailRenderer";
+import { GroupMetadataRenderer } from "./GroupMetadataRenderer";
 import { NostrEvent } from "@/types/nostr";
 import { BaseEventContainer, type BaseEventProps } from "./BaseEventRenderer";
 
@@ -116,6 +117,7 @@ const kindRenderers: Record<number, React.ComponentType<BaseEventProps>> = {
   31989: HandlerRecommendationRenderer, // Handler Recommendation (NIP-89)
   31990: ApplicationHandlerRenderer, // Application Handler (NIP-89)
   32267: ZapstoreAppRenderer, // Zapstore App
+  39000: GroupMetadataRenderer, // Group Metadata (NIP-29)
   39701: Kind39701Renderer, // Web Bookmarks (NIP-B0)
 };