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, 16 insertions, 0 deletions

diff --git a/dotfiles/common/.ssh/config b/dotfiles/common/.ssh/config
new file mode 100644
index 0000000..6f97ab5
--- /dev/null
+++ b/dotfiles/common/.ssh/config
@@ -0,0 +1,8 @@
+ControlMaster auto
+ControlPath ~/.ssh/%r@%h:%p
+IdentityFile ~/.ssh/id_ed25519
+ServerAliveCountMax=30
+ServerAliveInterval=5
+
+Host cjennings.net
+    LogLevel ERROR
diff --git a/dotfiles/common/.ssh/decrypt_ssh b/dotfiles/common/.ssh/decrypt_ssh
new file mode 100644
index 0000000..8d1f3e3
--- /dev/null
+++ b/dotfiles/common/.ssh/decrypt_ssh
@@ -0,0 +1 @@
+gpg --decrypt ssh.tar.gz.gpg | tar -zxf - 
diff --git a/dotfiles/common/.ssh/set_perms b/dotfiles/common/.ssh/set_perms
new file mode 100644
index 0000000..9927ebd
--- /dev/null
+++ b/dotfiles/common/.ssh/set_perms
@@ -0,0 +1,7 @@
+#!/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/common/.ssh/ssh.tar.gz.gpg b/dotfiles/common/.ssh/ssh.tar.gz.gpg
new file mode 100644
index 0000000..6f5a864
--- /dev/null
+++ b/dotfiles/common/.ssh/ssh.tar.gz.gpg