Leverage Playwright MCP For Prototype Validation

[flesheatinggames]

Design OS is awesome, but I found that more often than not the prototype apps would initially fail with some error or another. I could paste the error into CC and it would fix it and then we would carry on. But why do that when there's Playwright? I updated all the commands that generate prototypes to add a validation step using Playwright, and the errors fix themselves! I could submit a PR if you think this is valuable.