Add Linux support: cross-platform restart, nvidia-ml-py dep, README update

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

server/restart.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+# Restart the WLED Screen Controller server (Linux/macOS)
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+
+# Stop any running instance
+PIDS=$(pgrep -f 'wled_controller\.main' 2>/dev/null || true)
+if [ -n "$PIDS" ]; then
+    echo "Stopping server (PID $PIDS)..."
+    pkill -f 'wled_controller\.main' 2>/dev/null || true
+    sleep 2
+fi
+
+# Start server detached
+echo "Starting server..."
+cd "$SCRIPT_DIR"
+nohup python -m wled_controller.main > /dev/null 2>&1 &
+sleep 3
+
+# Verify it's running
+NEW_PID=$(pgrep -f 'wled_controller\.main' 2>/dev/null || true)
+if [ -n "$NEW_PID" ]; then
+    echo "Server started (PID $NEW_PID)"
+else
+    echo "WARNING: Server does not appear to be running!"
+fi