For me, the most underrated launch at DevDay: Sign in with ChatGPT. Everyone is talking about Dots. Users now pay $20 to ChatGPT, $20 to Notion, $20 to a coding tool. Same models underneath. BYOK never fixed it because normal people don't know what an API key is. Sign in with ChatGPT fixes it. Usage counts toward their ChatGPT limits. As a developer, you ship AI features with no inference bill. As a user, you pay once and control the budget per app. It's Sign in with Google/GitHub, but for…