降级 Conf 以修复后端打包问题；后端新增启动参数功能（含 help、port、loglevel）；新增服务器配置（含同时转码任务数、ffmpeg 路径）

Author: ttqftech

.vscode/launch.json

@@ -19,6 +19,7 @@
       // },
       "program": "${workspaceFolder}/src/backend/index.ts",
       "outFiles": ["${workspaceFolder}/app/backend/**/*.cjs"],
+      "args": ["--loglevel", "6"],
       // "skipFiles": [
       //     "<node_internals>/**"
       // ],

package.json

@@ -51,7 +51,7 @@
   },
   "dependencies": {
     "@khanacademy/simple-markdown": "^0.11.2",
-    "conf": "^13.0.1",
+    "conf": "10.2.0",
     "crypto-js": "^4.1.1",
     "events": "^3.3.0",
     "koa": "^2.14.1",