feat: introduce WebSocket sync for XBoard nodes

- Implement Workerman-based `xboard:ws-server` for real-time node synchronization.
- Support custom routes, outbounds, and certificate configurations via JSON.
- Optimize scheduled tasks with `lazyById` to minimize memory footprint.
- Enhance reactivity using Observers for `Plan`, `Server`, and `ServerRoute`.
- Expand protocol support for `httpupgrade`, `h2`, and `mieru`.

app/Services/NodeRegistry.php

@@ -0,0 +1,77 @@
+<?php
+
+namespace App\Services;
+
+use Workerman\Connection\TcpConnection;
+
+/**
+ * In-memory registry for active WebSocket node connections.
+ * Runs inside the Workerman process.
+ */
+class NodeRegistry
+{
+    /** @var array<int, TcpConnection> nodeId → connection */
+    private static array $connections = [];
+
+    public static function add(int $nodeId, TcpConnection $conn): void
+    {
+        // Close existing connection for this node (if reconnecting)
+        if (isset(self::$connections[$nodeId])) {
+            self::$connections[$nodeId]->close();
+        }
+        self::$connections[$nodeId] = $conn;
+    }
+
+    public static function remove(int $nodeId): void
+    {
+        unset(self::$connections[$nodeId]);
+    }
+
+    public static function get(int $nodeId): ?TcpConnection
+    {
+        return self::$connections[$nodeId] ?? null;
+    }
+
+    /**
+     * Send a JSON message to a specific node.
+     */
+    public static function send(int $nodeId, string $event, array $data): bool
+    {
+        $conn = self::get($nodeId);
+        if (!$conn) {
+            return false;
+        }
+
+        $payload = json_encode([
+            'event' => $event,
+            'data' => $data,
+            'timestamp' => time(),
+        ]);
+
+        $conn->send($payload);
+        return true;
+    }
+
+    /**
+     * Get the connection for a node by ID, checking if it's still alive.
+     */
+    public static function isOnline(int $nodeId): bool
+    {
+        $conn = self::get($nodeId);
+        return $conn !== null && $conn->getStatus() === TcpConnection::STATUS_ESTABLISHED;
+    }
+
+    /**
+     * Get all connected node IDs.
+     * @return int[]
+     */
+    public static function getConnectedNodeIds(): array
+    {
+        return array_keys(self::$connections);
+    }
+
+    public static function count(): int
+    {
+        return count(self::$connections);
+    }
+}