feat(windows): bundle PixelPass viewer

packaging/windows/INSTALL.md

@@ -21,8 +21,9 @@ it once, then you and I connect directly to each other.
 
 4. The setup window opens. Just keep clicking **Next**. Two checkboxes you'll
    see along the way:
-   - **"Allow PeerSpeak through Windows Firewall"** — leave this **checked**
-     (it lets the call connect without interruptions).
+   - **"Allow PeerSpeak and PixelPass through Windows Firewall"** — leave this
+     **checked** (it lets calls and incoming screen shares connect without
+     interruptions).
    - **"Create a desktop shortcut"** — check it if you'd like an icon on your
      desktop.
 
@@ -69,7 +70,19 @@ Either way works the same; it just depends on who makes the room.
 
 ---
 
-## 4. Chatting and sharing photos/files
+## 4. Watching a shared screen
+
+This Windows build can watch a screen shared by someone using PeerSpeak on
+Linux. Install [VLC](https://www.videolan.org/vlc/) (or mpv) first. When someone
+starts sharing, click **Watch** next to their name; the shared desktop opens in
+the player.
+
+Starting your own screen share from Windows is not available yet. The Windows
+build labels that control **Sharing unavailable** while keeping Watch enabled.
+
+---
+
+## 5. Chatting and sharing photos/files
 
 There's a **text chat** box at the bottom of the call window — type a message
 and press **Enter** to send it to everyone in the room.
@@ -102,6 +115,8 @@ A couple of notes:
   ticket — they're meant to be used right away. Also make sure we're both on the
   **same version** — if I've sent you an updated installer, install it (an old
   version and a new one can't connect to each other).
+- **"Watch doesn't open anything."** Install VLC, restart PeerSpeak, and try
+  Watch again. The PixelPass viewer is already included with PeerSpeak.
 - **The blue warning again.** Same as install: **More info → Run anyway**. It's
   the unsigned-app warning, not malware.