feat(wireguard): client config UX, collapsible config card, configurable DNS

Land the WireGuard client-config UX work on main (the upstream PR #5642
branch could not be pushed to).

- Reusable collapsible ConfigBlock (copy/download/QR, actions aligned right)
  for the client .conf, used by client info and the public sub page.
- Correct .conf: canonical PresharedKey casing and DNS sourced from the inbound
  (configurable per-inbound, default 1.1.1.1, 1.0.0.1).
- Configurable per-inbound DNS for WireGuard (schema + form + backend hint via
  InboundOption.WgDns); inert at the Xray layer.
- Public sub page now shows the WireGuard config, rebuilt from the share link;
  the Go wireguard:// link carries dns/presharedkey/keepalive for completeness.
- QR enabled for the wireguard:// link; link rows are compact like other protocols.
- Client information order is subscription, copy URL, WireGuard config; the
  redundant config tab is removed from the add/edit client modal.
- Drop the Inbound Information and QR Code row actions for WireGuard inbounds.

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

@@ -61,6 +61,7 @@ export type WireguardClient = z.infer<typeof WireguardClientSchema>;
 export const WireguardInboundSettingsSchema = z.object({
   mtu: optionalClearedInt(z.number().int().min(1)),
   secretKey: z.string().min(1),
+  dns: z.string().optional(),
   peers: z.array(WireguardInboundPeerSchema).default([]),
   clients: z.array(WireguardClientSchema).default([]),
   noKernelTun: z.boolean().default(false),