Drawbly local video renderer

Requires Node.js 22.14+ and FFmpeg/ffprobe on PATH.
Run npm install once, then node render-recipe.mjs example.video.json output.mp4
Rendering makes no network requests or AI API calls.
Keep image and narration assets beside the recipe. Keep narration beside exported recipes.
Full contract: https://drawbly.com/agent-video.html
Windows offline speech: powershell -NoProfile -File speak-local.ps1 -TextFile script.txt -Output narration.wav
