Show total zap amount (sats) instead of zap count on notes

- useEventStats now sums the `amount` tag (millisatoshis) from kind 9735
  zap receipts and returns `zapAmount` in sats instead of a zap count
- NoteCard displays the total with compact formatting (e.g. 1.2K, 3.5M)

Co-authored-by: shakespeare.diy <assistant@shakespeare.diy>

src/components/NoteCard.tsx

@@ -17,6 +17,13 @@ interface NoteCardProps {
   className?: string;
 }
 
+/** Formats a sats amount into a compact human-readable string. */
+function formatSats(sats: number): string {
+  if (sats >= 1_000_000) return `${(sats / 1_000_000).toFixed(1).replace(/\.0$/, '')}M`;
+  if (sats >= 1_000) return `${(sats / 1_000).toFixed(1).replace(/\.0$/, '')}K`;
+  return sats.toString();
+}
+
 /** Extracts image URLs from note content. */
 function extractImages(content: string): string[] {
   const urlRegex = /https?:\/\/[^\s]+\.(jpg|jpeg|png|gif|webp|svg)(\?[^\s]*)?/gi;
@@ -164,7 +171,7 @@ export function NoteCard({ event, className }: NoteCardProps) {
               onClick={(e) => e.stopPropagation()}
             >
               <Zap className="size-[18px]" />
-              {stats?.zaps ? <span className="text-xs">{stats.zaps}</span> : null}
+              {stats?.zapAmount ? <span className="text-xs">{formatSats(stats.zapAmount)}</span> : null}
             </button>
 
             {/* More */}

src/hooks/useTrending.ts

@@ -77,18 +77,27 @@ export function useEventStats(eventId: string | undefined) {
       let replies = 0;
       let reposts = 0;
       let reactions = 0;
-      let zaps = 0;
+      let zapAmount = 0;
 
       for (const e of events) {
         switch (e.kind) {
           case 1: replies++; break;
           case 6: reposts++; break;
           case 7: reactions++; break;
-          case 9735: zaps++; break;
+          case 9735: {
+            const amountTag = e.tags.find(([name]) => name === 'amount');
+            if (amountTag?.[1]) {
+              const msats = parseInt(amountTag[1], 10);
+              if (!isNaN(msats)) {
+                zapAmount += Math.floor(msats / 1000);
+              }
+            }
+            break;
+          }
         }
       }
 
-      return { replies, reposts, reactions, zaps };
+      return { replies, reposts, reactions, zapAmount };
     },
     enabled: !!eventId,
     staleTime: 60 * 1000,