swarm-ui: the egress icon is shown as an emoji like the others

The globe of the egress card and of the allowed-domains box showed as a
plain monochrome glyph where the bee and the bell were emoji: a font with a
text-style glyph for the globe won over the emoji font. The two globes now carry
the emoji variation selector, and a panel's icon asks for emoji presentation
(font-variant-emoji), so another icon cannot fall the same way.

frontend/packages/swarm-ui/src/agent/detail/AllowedDomains.tsx

@@ -196,7 +196,7 @@ export function AddForm({
   return (
     <Panel
       title={`${deny ? "denied" : "allowed"} domain — ${agent ?? "swarm-wide"}`}
-      icon="🌐"
+      icon={"🌐\uFE0F"}
       onClose={onClose}
     >
       <p>