Document the redesigned NetBird desktop app (release candidate) (#802)

* Add RC notes and documentation

* Add download links

* Updates lang and daemon

src/pages/get-started/install/linux.mdx

@@ -4,6 +4,21 @@ import {Note} from "@/components/mdx";
 
 The NetBird client (agent) allows a peer to join a pre-existing NetBird deployment. If a NetBird deployment is not yet available, there are both managed and [self-hosted](https://docs.netbird.io/selfhosted/selfhosted-quickstart) options available.
 
+## Desktop App Dependencies
+
+<Note>
+    This applies to the redesigned NetBird desktop app, currently available as a **release candidate** ([v0.75.0-rc.1](https://github.com/netbirdio/netbird/releases/tag/v0.75.0-rc.1)). The current stable GUI does not require these packages.
+</Note>
+
+The redesigned desktop app renders its interface in a GTK 4 WebKit webview. Linux distributions package these libraries under inconsistent names, so install them manually before launching the GUI.
+
+**Debian / Ubuntu**
+
+```bash
+sudo apt-get install libgtk-4-1 libwebkitgtk-6.0-4 xdg-utils
+```
+
+On other distributions, install the equivalent **GTK 4**, **WebKitGTK 6.0**, and **xdg-utils** packages from your package manager.
 
 ## Linux Install Script