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>

4 files changed, 0 insertions, 16 deletions

diff --git a/dotfiles/system/.ssh/config b/dotfiles/system/.ssh/config
deleted file mode 100644
index 6f97ab5..0000000
--- a/dotfiles/system/.ssh/config
+++ /dev/null
@@ -1,8 +0,0 @@
-ControlMaster auto
-ControlPath ~/.ssh/%r@%h:%p
-IdentityFile ~/.ssh/id_ed25519
-ServerAliveCountMax=30
-ServerAliveInterval=5
-
-Host cjennings.net
-    LogLevel ERROR
diff --git a/dotfiles/system/.ssh/decrypt_ssh b/dotfiles/system/.ssh/decrypt_ssh
deleted file mode 100644
index 8d1f3e3..0000000
--- a/dotfiles/system/.ssh/decrypt_ssh
+++ /dev/null
@@ -1 +0,0 @@
-gpg --decrypt ssh.tar.gz.gpg | tar -zxf - 
diff --git a/dotfiles/system/.ssh/set_perms b/dotfiles/system/.ssh/set_perms
deleted file mode 100644
index 9927ebd..0000000
--- a/dotfiles/system/.ssh/set_perms
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/sh
-# sets permissions for ssh folders and files 
-
-cd "$HOME"
-chmod 700 "$HOME"/.ssh
-chmod 600 "$HOME"/.ssh/*
-chmod 644 -f  "$HOME"/.ssh/*.pub  "$HOME"/.ssh/authorized_keys  "$HOME"/.ssh/known_hosts  "$HOME"/.ssh/config
diff --git a/dotfiles/system/.ssh/ssh.tar.gz.gpg b/dotfiles/system/.ssh/ssh.tar.gz.gpg
deleted file mode 100644
index 6f5a864..0000000
--- a/dotfiles/system/.ssh/ssh.tar.gz.gpg
+++ /dev/null