Add server CLI tools installer for Ubuntu/Debian servers

Introduce a self-contained repo with an interactive install.sh that
provisions zsh, oh-my-zsh, aliases, bat/yazi configs, docker shortcuts,
and git-delta pager setup. Configs are adapted from dotfiles for SSH-only
servers — no desktop or neovim dependencies.

Installer supports --all, --update (git pull + re-run), and --uninstall
with backup restore. Core packages include vim (default editor), yazi via
apt, and idempotent apt installs with warnings for eza and git-delta when
repos lack them.

configs/zsh/zhann-elvis.zsh-theme

@@ -0,0 +1,29 @@
+autoload -Uz vcs_info
+
+zstyle ':vcs_info:*' stagedstr '%F{green}●'
+zstyle ':vcs_info:*' unstagedstr '%F{yellow}●'
+zstyle ':vcs_info:*' check-for-changes true
+zstyle ':vcs_info:svn:*' branchformat '%b'
+zstyle ':vcs_info:svn:*' formats ' [%b%F{1}:%F{11}%i%c%u%B%F{green}]'
+zstyle ':vcs_info:*' enable git svn
+
+theme_precmd () {
+  if [[ -z $(git ls-files --other --exclude-standard 2> /dev/null) ]]; then
+    zstyle ':vcs_info:git:*' formats ' [%b%c%u%B%F{green}]'
+  else
+    zstyle ':vcs_info:git:*' formats ' [%b%c%u%B%F{red}●%F{green}]'
+  fi
+
+  vcs_info
+}
+
+setopt prompt_subst
+PROMPT='%B%F{33}%c%B%F{green}${vcs_info_msg_0_}%B%F{magenta} %{$reset_color%}% '
+
+autoload -U add-zsh-hook
+add-zsh-hook precmd  theme_precmd
+
+# to preview colors
+# for i in {0..255}; do
+#   print -P "%F{$i}$i%f "
+# done