feat: rebuild master from the live desktop, and add the KDE configuration

master still carried the 2021 tree. Task 6 does a checkout over $HOME, so nine
of those files would have overwritten the current configuration rather than
updated it - i3, sway, dunst, nvim, vim and tmux, all diverged by years. The
plan had no step for this; the design warned about it and then nothing
implemented the warning.

The nine are now taken from the live machine verbatim, and the 31 files with no
counterpart there are dropped. Everything remains on archive/2021-i3-sway.
README.md and .scripts/install.sh are kept despite having no live counterpart:
the first documents the repository and the second is what ls.shron.de/dotconf
serves, so deleting it would break that link.

Verified byte-identical to the live files afterwards, which is the point - a
checkout on this machine must change nothing.

KDE has been in daily use for a while with nothing backing it up. Eighteen rc
files and the nine autostart entries are added: window rules and shortcuts,
notification behaviour, the lock screen, and the panel layout in
plasma-org.kde.plasma.desktop-appletsrc. That last one is rewritten by
plasmashell whenever anything moves, so it will produce churn - kept anyway,
since a lost panel layout is the most tedious thing here to rebuild by hand.

.config/kdeconnect/ is excluded rather than added. It holds the device
certificate and its private key, and is pairing state rather than
configuration - the only place under .config that carries a secret.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

.gitignore

@@ -25,6 +25,11 @@ id_*
 .zshrc.pre-dotconfs
 .config-backup/
 
+# KDE Connect keeps the device certificate and its private key here. Pairing
+# state, not configuration - and the one place under .config that actually
+# holds a secret.
+.config/kdeconnect/
+
 # Runtime state and caches.
 .zsh_history
 .zcompdump*