feat(engine): 优化字幕引擎输出格式、准备合并两个字幕引擎

- 重构字幕引擎相关代码
- 准备合并两个字幕引擎

package-lock.json

@@ -22,6 +22,7 @@
         "@electron-toolkit/eslint-config-ts": "^3.0.0",
         "@electron-toolkit/tsconfig": "^1.0.1",
         "@types/node": "^22.14.1",
+        "@types/pidusage": "^2.0.5",
         "@vitejs/plugin-vue": "^5.2.3",
         "electron": "^35.1.5",
         "electron-builder": "^25.1.8",
@@ -2296,6 +2297,13 @@
         "undici-types": "~6.21.0"
       }
     },
+    "node_modules/@types/pidusage": {
+      "version": "2.0.5",
+      "resolved": "https://registry.npmmirror.com/@types/pidusage/-/pidusage-2.0.5.tgz",
+      "integrity": "sha512-MIiyZI4/MK9UGUXWt0jJcCZhVw7YdhBuTOuqP/BjuLDLZ2PmmViMIQgZiWxtaMicQfAz/kMrZ5T7PKxFSkTeUA==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/@types/plist": {
       "version": "3.0.5",
       "resolved": "https://registry.npmmirror.com/@types/plist/-/plist-3.0.5.tgz",