feat(engine): 重构字幕引擎并实现 WebSocket 通信

- 重构了 Gummy 和 Vosk 字幕引擎的代码，提高了可扩展性和可读性
- 合并 Gummy 和 Vosk 引擎为单个可执行文件
- 实现了字幕引擎和主程序之间的 WebSocket 通信，避免了孤儿进程问题

engine/utils/server.py

@@ -0,0 +1,37 @@
+import socket
+import threading
+import json
+from utils import thread_data, stdout_cmd, stderr
+
+
+def handle_client(client_socket):
+    global thread_data
+    while True:
+        try:
+            data = client_socket.recv(4096).decode('utf-8')
+            if not data:
+                break
+            data = json.loads(data)
+
+            if data['command'] == 'stop':
+                if thread_data.status == 'running':
+                    thread_data.status = 'stop'
+                    break
+        except Exception as e:
+            stderr(f'Communication error: {e}')
+            break
+    
+    thread_data.status = 'stop'
+    client_socket.close()
+
+
+def start_server(port: int):
+    server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    server.bind(('localhost', port))
+    server.listen(1)
+    stdout_cmd('ready')
+
+    client, addr = server.accept()
+    client_handler = threading.Thread(target=handle_client, args=(client,))
+    client_handler.daemon = True
+    client_handler.start()