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.

internal/web/translation/en-US.json

@@ -718,6 +718,8 @@
       "tabBasics": "Basics",
       "tabCredentials": "Credentials",
       "tabLinks": "Links",
+      "wireguardConfig": "WireGuard config",
+      "conf": "CONF",
       "linksHint": "Add third-party share links and remote subscription URLs to include in this client's subscription.",
       "addExternalLink": "Add External Link",
       "addExternalSubscription": "Add External Subscription",