[sofixa]

For browser tabs browser sync is pretty much a solved problem ( no idea how well Safari does this, but Firefox and Chromium-based browsers have been good for years). For files, it'd require some discipline and tooling - using a cloud sync service like Dropbox or OneDrive or whatever, and always putting important files in places where it'd be synced. Also, with a remote access service ( Chrome Remote Desktop? Wireguard VPN + VNC? Whatever works best for you) you could keep access to your desktop remotely from your laptop if you need to grab a file last minute.

[gnicholas]

Does browser tab sync require signing or something? I feel like I've never seen this (but if I had, I would have ignored it, since I don't have another computer to sync my tabs to!).

[sofixa]

Yep, you have to create a profile in your browser of choice.

Note: it doesn't magically copy all tabs, but history is shared, and on Chrome there's a "tabs on other devices" bit where you can see open tabs on your other logged in devices. (Including from mobile)