Fix FFmpeg compatibility issues for async video operations - replace fluent-ffmpeg dependency (#1859)

Author: Copilot

docs/public/genaiscript.d.ts

@@ -11,7 +11,6 @@
   "devDependencies": {
     "@genaiscript/eslint-plugin-genaiscript": "workspace:*",
     "@types/debug": "catalog:",
-    "@types/fluent-ffmpeg": "^2.1.27",
     "@types/html-to-text": "^9.0.4",
     "@types/ini": "^4.1.1",
     "@types/mdast": "^4.0.4",
@@ -74,7 +73,6 @@
     "fetch-retry": "^6.0.0",
     "fflate": "^0.8.2",
     "file-type": "^21.0.0",
-    "fluent-ffmpeg": "^2.1.3",
     "gpt-tokenizer": "^3.0.1",
     "groq-js": "^1.17.3",
     "html-escaper": "3.0.3",