Security: the --control server requires an auth token and closes bad connections (#777)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

Cargo.lock

@@ -1503,7 +1503,9 @@ dependencies = [
  "eframe",
  "egui",
  "fmv-macos-events",
+ "getrandom 0.4.3",
  "gridcraft-engine",
+ "gridcraft-mcp",
  "gridcraft-ui-egui",
  "image",
  "log",