fix: remove yellow text color from regular supporters, keep only badge

Regular supporters (who zapped but not 2.1k+/month) should only show the
yellow zap badge next to their name, not have their username colored yellow.

Changes:
- Remove yellow text color (text-yellow-500) from regular supporters
- Regular supporters now: normal username color + yellow zap badge
- Premium supporters still: normal username color + badge in username color
- Updated component documentation to reflect this change

This provides cleaner visual hierarchy where only Grimoire team members
get special username colors (gradient), while supporters are distinguished
by their badge alone.

src/components/nostr/UserName.tsx

@@ -23,7 +23,7 @@ interface UserNameProps {
  * - BadgeCheck icon that scales with username size
  * Shows Grimoire supporters (non-members who zapped):
  * - Premium supporters (2.1k+ sats/month): Zap badge in their username color
- * - Regular supporters: Yellow text + filled yellow zap icon
+ * - Regular supporters: Yellow zap badge (no username color change)
  */
 export function UserName({ pubkey, isMention, className }: UserNameProps) {
   const { addWindow, state } = useGrimoire();
@@ -55,11 +55,9 @@ export function UserName({ pubkey, isMention, className }: UserNameProps) {
             ? isActiveAccount
               ? "bg-gradient-to-tr from-orange-400 to-amber-600 bg-clip-text text-transparent"
               : "bg-gradient-to-tr from-violet-500 to-fuchsia-600 bg-clip-text text-transparent"
-            : isSupporter && !isPremiumSupporter
-              ? "text-yellow-500"
-              : isActiveAccount
-                ? "text-highlight"
-                : "text-accent",
+            : isActiveAccount
+              ? "text-highlight"
+              : "text-accent",
         )}
       >
         {isMention ? "@" : null}