Put HE (dns.he.net) in your back pocket - they run a free DNS service which includes slave (do we still call it that?) service so that you can add their resolver as an ultimate failover / failback if your self hosted DNS takes a dive for whatever reason things break in our world.

Generally, hosting your own DNS “should” mean having a primary and secondary on separate AS networks, or at least different provider routes or locations. But if you’re doing all this from home, where is the second location for DR purposes… exactly? I sure don’t have one, power goes out here everything goes dark - in the old days everyone used to do this (share out tertiary DNS to each other) but it’s become a thing of the past in today’s world. HE can help fill that gap.

To your point - I use Gcore DNS and Bunny DNS for my stuff, as I mainly use online VPSes and don’t run racks of hardware at the house. The only things I physically selfhost at home are a pair of old laptops acting as storage servers which backup all my bytes and bits from online to some SSDs.

The above said, it wasn’t hard to find a project using XDG and a JSON mapping file (basically your idea fleshed out in python) to get where you want to go if XDG is enough: https://github.com/JonTheNiceGuy/usbrowser

You’re not going to like this answer - there’s a bunch of different ways depending on the app(s) and the desktop environment. The Arch wiki goes over it in detail: https://wiki.archlinux.org/title/Default_applications

I would guess that focusing on the XDG spec and covering Gnome, KDE and Xfce (Xfce can be replaced with anything else like Cinnamon that comes with Mint, “non Gnome or KDE”) is the best plan of attack for what matters to 80%+ of the population.

I would assume your system is using systemd (I don’t use Kubuntu specifically); the laptop lid is (now in 2026) controlled by the systemd infrastructure - it’s a matter of setting a config option and this should fix you up. Arch as usual has the best wiki on the subject:

https://wiki.archlinux.org/title/Power_management#ACPI_events

You’re probably looking at HandleLidSwitch* options. There’s still nothing wrong with the manual disable to /proc/acpi/wakeup to cover your bases (layers of the onion), I’m fighting with a “modern” laptop that only has s2idle and it’s terrible compared to S3 - I’m in ACPI wakeup hell and still trying to figure out what’s causing it.