feat: update _ member pubkey and add diagonal gradient styling

Updates the _ member pubkey and enhances the visual styling with a more
stylish diagonal gradient effect.

Changes:
- Update _ member pubkey to c8fb0d3a... (new pubkey)
- Change gradient from horizontal to diagonal (bg-gradient-to-br)
- Add middle color stop (via-orange-400) for smoother gradient
- Updated nostr.json with new _ pubkey
- Updated all tests with correct pubkey
- Chat system already uses UserName component (verified)

Member usernames now display with a vibrant yellow-to-orange diagonal
gradient that flows from top-left to bottom-right with smooth transitions.

public/.well-known/nostr.json

@@ -1,6 +1,6 @@
 {
   "names": {
-    "_": "60dfe8bda41b70736ae9a16385fa95c8d76792746c6f5e0a6249223e8779c667",
+    "_": "c8fb0d3aa788b9ace4f6cb92dd97d3f292db25b5c9f92462ef6c64926129fbaf",
     "verbiricha": "7fa56f5d6962ab1e3cd424e758c3002b8665f7b0d8dcee9fe9e288d7751ac194"
   }
 }

src/components/nostr/UserName.tsx

@@ -41,7 +41,7 @@ export function UserName({ pubkey, isMention, className }: UserNameProps) {
       className={cn(
         "font-semibold cursor-crosshair hover:underline hover:decoration-dotted",
         isGrimoire
-          ? "bg-gradient-to-r from-yellow-400 to-orange-500 bg-clip-text text-transparent"
+          ? "bg-gradient-to-br from-yellow-400 via-orange-400 to-orange-500 bg-clip-text text-transparent"
           : isActiveAccount
             ? "text-highlight"
             : "text-accent",

src/lib/grimoire-members.test.ts

@@ -10,7 +10,7 @@ import {
 
 describe("Grimoire Members", () => {
   const underscorePubkey =
-    "60dfe8bda41b70736ae9a16385fa95c8d76792746c6f5e0a6249223e8779c667";
+    "c8fb0d3aa788b9ace4f6cb92dd97d3f292db25b5c9f92462ef6c64926129fbaf";
   const verbirichaPubkey =
     "7fa56f5d6962ab1e3cd424e758c3002b8665f7b0d8dcee9fe9e288d7751ac194";
   const randomPubkey =

src/lib/grimoire-members.ts

@@ -24,7 +24,7 @@ export interface GrimoireMember {
 export const GRIMOIRE_MEMBERS: readonly GrimoireMember[] = [
   {
     username: "_",
-    pubkey: "60dfe8bda41b70736ae9a16385fa95c8d76792746c6f5e0a6249223e8779c667",
+    pubkey: "c8fb0d3aa788b9ace4f6cb92dd97d3f292db25b5c9f92462ef6c64926129fbaf",
     nip05: "_@grimoire.rocks",
   },
   {

src/lib/nip05.test.ts

@@ -10,7 +10,7 @@ describe("NIP-19 Decoding for Grimoire Members", () => {
     expect(decoded.type).toBe("nprofile");
     if (decoded.type === "nprofile") {
       expect(decoded.data.pubkey).toBe(
-        "60dfe8bda41b70736ae9a16385fa95c8d76792746c6f5e0a6249223e8779c667",
+        "c8fb0d3aa788b9ace4f6cb92dd97d3f292db25b5c9f92462ef6c64926129fbaf",
       );
     }
   });