add GStreamer helper scripts

scripts/start_stream.sh

@@ -0,0 +1,9 @@
+#!/bin/bash
+# Quick start script - starts streaming with default pipeline
+
+SOCKET="/tmp/vizion_control.sock"
+
+echo "Starting stream with default pipeline (videoconvert ! autovideosink)..."
+echo '{"command":"start_stream"}' | socat - UNIX-CONNECT:$SOCKET
+
+echo "Stream started. Use stop_stream.sh to stop."