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, 20 insertions, 0 deletions

diff --git a/dotfiles/common/.local/share/applications/emacsclient-mail.desktop b/dotfiles/common/.local/share/applications/emacsclient-mail.desktop
new file mode 100644
index 0000000..6efcf61
--- /dev/null
+++ b/dotfiles/common/.local/share/applications/emacsclient-mail.desktop
@@ -0,0 +1,20 @@
+[Desktop Entry]
+Categories=Network;Email;
+Comment=Emacs is my mail client
+Exec=sh -c "exec emacsclient --alternate-editor= --display=\\"\\$DISPLAY\\" --eval \\\\(message-mailto\\\\ \\\\\\"%u\\\\\\"\\\\)"
+Icon=emacs
+Name=Emacs (Mail, Client)
+MimeType=x-scheme-handler/mailto;
+NoDisplay=true
+Terminal=false
+Type=Application
+Keywords=emacsclient;
+Actions=new-window;new-instance;
+
+[Desktop Action new-window]
+Name=New Window
+Exec=/usr/bin/emacsclient --alternate-editor= --create-frame --eval "(message-mailto \\"%u\\")"
+
+[Desktop Action new-instance]
+Name=New Instance
+Exec=emacs -f message-mailto %u