fix: resolve meteor WebSocket race condition and setup apt-get failure

Meteor: onopen callback used closure variable _ws instead of `this`,
so a double-click during CONNECTING state sent on the wrong socket.
Also clean up any in-progress connection on re-start, not just running ones.

Setup: make apt-get update non-fatal so third-party repo errors
(e.g. stale PPAs on Debian) don't abort the entire install.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

setup.sh

@@ -1370,7 +1370,10 @@ install_debian_packages() {
   CURRENT_STEP=0
 
   progress "Updating APT package lists"
-  $SUDO apt-get update -y >/dev/null
+  if ! $SUDO apt-get update -y >/dev/null 2>&1; then
+    warn "apt-get update reported errors (possibly from third-party repos on your system)."
+    warn "Continuing anyway — if package installs fail, check your APT sources."
+  fi
 
   progress "Installing RTL-SDR"
   if ! $IS_DRAGONOS; then