Ubuntu-Encyclopedia

Ubuntu documentation-first workflow for Ubuntu-specific questions, maintenance, updates, upgrades, package management, system administration, service troubleshooting, networking, storage, logs, release behavior, and diagnostics. Use when the request materially depends on Ubuntu or Ubuntu-specific tooling/behavior such as Ubuntu release behavior, `apt`/`apt-get`/`dpkg`/`snap`, `systemd`/`systemctl`/`journalctl`, Netplan, NetworkManager, package repair, repository/key issues, service failures, boot issues, mounts/`fstab`, permissions, users/groups, or non-trivial Ubuntu maintenance/troubleshooting. Do not use for generic shell, git, Python, Docker, or Linux questions unless Ubuntu-specific semantics matter.