refactor(dotfiles): rename system/ to common/ and remove unused configs

Rename dotfiles/system to dotfiles/common for clarity - indicates
shared dotfiles used across all desktop environments (DWM, Hyprland).

Removed config directories for uninstalled applications:
- ghostty (using different terminal)
- lf (using ranger instead)
- mopidy (using mpd instead)
- nitrogen (X11-only, obsolete for Wayland)
- pychess (not installed)
- JetBrains (not installed via archsetup)
- youtube-dl (using yt-dlp with different config location)

Kept audacious config for potential future use.

Updated all references in archsetup, CLAUDE.md, todo.org, and
validation.sh.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/dotfiles/common/.config/systemd/user/emacs.service b/dotfiles/common/.config/systemd/user/emacs.service
new file mode 100644
index 0000000..0e3a102
--- /dev/null
+++ b/dotfiles/common/.config/systemd/user/emacs.service
@@ -0,0 +1,19 @@
+[Unit]
+Description=Emacs text editor
+Documentation=info:emacs man:emacs(1) https://gnu.org/software/emacs/
+
+[Service]
+Type=notify
+ExecStart=/home/cjennings/.local/bin/emacs --fg-daemon
+
+# Emacs will exit with status 15 after having received SIGTERM, which
+# is the default "KillSignal" value systemd uses to stop services.
+SuccessExitStatus=15
+
+# The location of the SSH auth socket varies by distribution, and some
+# set it from PAM, so don't override by default.
+# Environment=SSH_AUTH_SOCK=%t/keyring/ssh
+Restart=on-failure
+
+[Install]
+WantedBy=default.target