I use Google AI Studio on three machines. My laptop, my desktop, and occasionally a work machine. Every time I switched devices, my system instructions weren't there. I'd carefully crafted a "Software Architect" prompt, a "Posts & Content" persona, a "YT Expert" context — and they existed on exactly one device. The others were blank. Chrome sync handles bookmarks, passwords, even open tabs. Why not this? The Obvious Solution That Doesn't Work chrome.storage.sync looks like exactly the right tool. It's built into Chrome, it syncs across devices on the same Google account, and it has a reasonable quota. There's one catch: Chrome only syncs extension storage for extensions installed from the Chrome Web Store. Sideloaded extensions — installed via Developer Mode from a local folder — get a randomly generated ID on each device. Different ID = different sync namespace. Your data never overlaps, even with the same Google account signed in.…