refactor(vpn): drop the 'This device' heading

The card sits directly under the connection toggle and shows this device's own name,
address and key expiry. The only other card that could be confused with it is the peer
list, which is plainly a list. A heading that repeats what the content already says
costs a line of vertical space on a phone and tells nobody anything.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

src/vpn/VpnScreen.tsx

@@ -1169,8 +1169,10 @@ const ThisDevice = ({ vm }: { vm: VpnVM }) => {
 
   return (
     <Card>
-      <Text className="font-bold" style={{ color: palette.text, fontSize: 14 }}>This device</Text>
-
+      {/* No "This device" heading. The card sits under the connection toggle showing this device's own
+          name, address and key expiry — the only card on the screen that could be about anything else
+          is the peer list, which is plainly a list. A label that repeats what the content already says
+          costs a line of vertical space on a phone and tells nobody anything. */}
       <View className="gap-0.5">
         <Text className="text-lg font-semibold" style={{ color: palette.text }}>
           {self.hostName || self.name}