feat(wireguard): per-peer comments for identifying devices (#5168)

WG peers were only identifiable by their keys. Add an optional panel-side
comment per peer: editable in the inbound form (echoed next to "Peer N"
in the section header), stored in the settings JSON alongside the
panel-only privateKey (xray-core ignores unknown peer fields), and
appended to the share link / .conf remark so the device is identifiable
in client apps too.

frontend/src/schemas/protocols/inbound/wireguard.ts

@@ -26,6 +26,10 @@ export const WireguardInboundPeerSchema = z.object({
   preSharedKey: z.string().optional(),
   allowedIPs: z.array(z.string()).default([]),
   keepAlive: optionalClearedInt(z.number().int().min(0)),
+  // Panel-only annotation (#5168): which client/device this peer belongs to.
+  // Rides along in the settings JSON like privateKey does; xray-core ignores
+  // unknown peer fields.
+  comment: z.string().optional(),
 });
 export type WireguardInboundPeer = z.infer<typeof WireguardInboundPeerSchema>;