Add embedded VNC server with JWT auth and per-peer toggle

client/internal/engine_vnc_console_linux.go

@@ -0,0 +1,28 @@
+//go:build linux && !android
+
+package internal
+
+import (
+	"fmt"
+
+	vncserver "github.com/netbirdio/netbird/client/vnc/server"
+)
+
+// newConsoleVNC builds a framebuffer + uinput VNC backend for boxes
+// without a running X server. Used as the auto-fallback when
+// newPlatformVNC can't reach X. Returns an error when /dev/fb0 or
+// /dev/uinput aren't usable so the caller can drop back to a stub.
+func newConsoleVNC() (vncserver.ScreenCapturer, vncserver.InputInjector, error) {
+	poller := vncserver.NewFBPoller("")
+	w, h := poller.Width(), poller.Height()
+	if w == 0 || h == 0 {
+		poller.Close()
+		return nil, nil, fmt.Errorf("framebuffer capturer init failed (is /dev/fb0 readable?)")
+	}
+	inj, err := vncserver.NewUInputInjector(w, h)
+	if err != nil {
+		poller.Close()
+		return nil, nil, fmt.Errorf("uinput init: %w", err)
+	}
+	return poller, inj, nil
+}