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/custom_tools/backup_dotfiles.sh

@@ -0,0 +1,30 @@
+#!/bin/bash
+
+# TODO: update REPO_URL once remote is set up (Gitea or GitHub)
+REPO_URL="https://github.com/neurobrko/server_cli_tools/archive/refs/heads/main.tar.gz"
+BACKUP_DIR="$HOME/.server_cli_tools_bkp"
+DRY_RUN=false
+
+if [[ "$1" == "--dry-run" ]]; then
+    DRY_RUN=true
+    echo "Dry run mode — no files will be moved."
+fi
+
+curl -s -L "$REPO_URL" | \
+tar -tzf - | \
+grep -v '/$' | \
+while read -r file; do
+    target="${file#*/}"
+
+    target_path="$HOME/$target"
+
+    if [ -f "$target_path" ]; then
+        if $DRY_RUN; then
+            echo "Would move $target_path to $BACKUP_DIR/$target"
+        else
+            echo "Moving $target_path to $BACKUP_DIR/$target"
+            mkdir -p "$(dirname "$BACKUP_DIR/$target")"
+            mv "$target_path" "$BACKUP_DIR/$target"
+        fi
+    fi
+done