Keep the personal half of the desktop in one place, and ask before installing it

Agent instructions, skills, SSH host aliases and expansion triggers are worth
having identical on every machine one person owns, and belong in none of the
shared configuration. They live in user/ now, with a manifest saying where each
piece goes and a link-user stage that puts it there.

That stage does nothing unless the machine said yes. Somebody who clones Panama
to try the desktop keeps their own ~/.claude/CLAUDE.md exactly where it was;
the question names the destinations and defaults to no. Anything displaced goes
to config/old rather than being deleted.

~/.claude/CLAUDE.md and ~/.codex/AGENTS.md were byte-identical copies of one
file, which is the drift this exists to prevent.

Also adds the vitals toggles for the battery and Claude usage readouts, which
had preferences and no way to reach them.

README.md

@@ -28,6 +28,7 @@ in order, without stopping again:
 | `interview` | Every prompt, before anything is installed. Answers last one run and are never written to a durable path |
 | `install-packages` | Repos (RPM Fusion, Terra, Hyprland COPR), the package lists in `setup/packages/`, then whichever optional categories were chosen |
 | `link-dotfiles` | Symlinks `config/dot/<name>` → `~/.config/<name>`, and seeds the wallpaper, cursor theme and Firefox chrome |
+| `link-user` | Links the personal content in `user/` — agent instructions, SSH host aliases — but only on a machine that answered yes. See [user/README.md](user/README.md) |
 | `change-settings` | Copies `config/copy/` over `/`, applies gsettings, enables user services |
 | `link-vicinae-scripts` | Publishes the Vicinae script commands |
 | `setup-identity` | git config, `gh auth login`, an SSH key — whichever were asked for |
@@ -135,7 +136,7 @@ docs/           Settings reference, and the design specs behind the work
 
 ## Tests
 
-151 of them, under `tests/`. Run the lot, or a subset by pattern:
+152 of them, under `tests/`. Run the lot, or a subset by pattern:
 
 ```sh
 panama test           # everything