Get scripts/configs and instructions set up for having local app-server run "on host" (ie. outside of k8s), and with vscode debugging enabled

[Venryx]

Core things to solve:

• Adjust the app-server's code so that it can detect when it is running outside of docker/k8s, and connect through a k8s proxy to the database pod, rather than using the k8s-internal DNS resolution system like is usually used. (as seen in the DB_ADDR environment-variable value)

Extra tasks: (good if you can get these done, but not needed immediately, so can be skipped if too troublesome)

• Ensure that VSCode's config files are set up properly to be able to do breakpoint-based debugging of the app-server program (when run outside of k8s). This may require installation of a debugger extension for vscode of one type or another, either for cpp and rust, or for rust specifically. (if a separate extension isn't required, that's even better ofc)