Install basic CLI tools (git curl wget + nslookup/kubectl) and document chmod

- ESSENTIAL now includes wget.
- Add best-effort CLI tools: htop, fzf, nslookup (dnsutils on Debian,
  bind-tools on Alpine).
- Attempt kubectl only when its package is available in the repos
  (not in default Debian/Alpine repos; install manually otherwise).
- README: add 'chmod +x install.sh' and a single-line
  clone+install+remove one-liner.

install.sh

@@ -3,7 +3,8 @@
 #
 # What it does:
 #   1. Detects the OS and package manager (apt on Debian, apk on Alpine).
-#   2. Installs base tooling (git, curl, zsh, vim) + extras (htop, fzf).
+#   2. Installs base tooling (git, curl, wget, zsh, vim) + CLI tools
+#      (htop, fzf, nslookup, kubectl when available) for both distros.
 #   3. Installs oh-my-zsh (unattended) and the zsh-autosuggestions plugin.
 #   4. Deploys the generic server/ dotfiles.
 #   5. Installs Vim plugins (clones each plugin declared in .vimrc).
@@ -98,18 +99,21 @@ detect_os() {
 # ----------------------------------------------------------------------------
 install_packages() {
     info "Installing base packages"
-    ESSENTIAL="git curl zsh vim"
-    # Extras kept lean + cross-distro safe:
-    #   htop  - process monitor (in main repos on both Debian & Alpine)
-    #   fzf   - fuzzy finder (community repo on Alpine, main on Debian)
-    # neofetch is intentionally NOT in the default set: it was removed from
-    # Alpine 3.20+, and on armbian/Debian it conflicts with the armbian-config
-    # package's own /usr/bin/neofetch (dpkg abort). Add it manually if wanted.
-    EXTRA="htop fzf"
+    # Always-present on both Debian and Alpine main/community repos.
+    ESSENTIAL="git curl wget zsh vim"
+    # Cross-distro CLI tools. Package names differ between distros:
+    #   nslookup  -> dnsutils (Debian) / bind-tools (Alpine)
+    #   fzf       -> community repo on Alpine, main on Debian
+    #   htop      -> main on both
+    if [ "$PKG" = "apk" ]; then
+        CLI_TOOLS="htop fzf bind-tools"
+    else
+        CLI_TOOLS="htop fzf dnsutils"
+    fi
 
     if [ "$PKG" = "apk" ]; then
-        # On Alpine, vim/fzf live in the 'community' repo, which is commented
-        # out by default in /etc/apk/repositories. Enable it (idempotent).
+        # On Alpine, vim/fzf/kubectl live in the 'community' repo, which is
+        # commented out by default in /etc/apk/repositories. Enable it (idempotent).
         info "Ensuring Alpine community repository is enabled"
         run sed -i -E "s|^#(.*/community)$|\1|" /etc/apk/repositories
         run $MGR_UPDATE
@@ -118,16 +122,33 @@ install_packages() {
     fi
 
     info "Installing essential packages"
-    run $MGR_ADD $ESSENTIAL
-
-    # Extras (htop, neofetch, fzf) are best-effort: a missing one must not
-    # abort the whole bootstrap (e.g. neofetch was dropped from Alpine 3.20+,
-    # and Debian/Ubuntu increasingly ship it as 'neofetch' but sometimes omit it).
-    info "Installing extra packages (best-effort)"
-    if run $MGR_ADD $EXTRA; then
-        ok "Extra packages installed"
+    if run $MGR_ADD $ESSENTIAL; then
+        ok "Essential packages installed"
     else
-        warn "Some extra packages failed to install (non-fatal)."
+        die "Failed to install essential packages ($ESSENTIAL)."
+    fi
+
+    # CLI tools are best-effort: a missing one must not abort the whole
+    # bootstrap (e.g. some tools simply aren't in the default repos).
+    info "Installing CLI tools (best-effort): $CLI_TOOLS"
+    if run $MGR_ADD $CLI_TOOLS; then
+        ok "CLI tools installed"
+    else
+        warn "Some CLI tools failed to install (non-fatal)."
+    fi
+
+    # kubectl is NOT in the default Debian/Alpine repos (it needs the
+    # Kubernetes apt repo / a manual install). Install it only if the package
+    # is actually available, so the script stays generic and repo-agnostic.
+    if command -v kubectl >/dev/null 2>&1; then
+        ok "kubectl already present, skipping"
+    else
+        info "Attempting to install kubectl (if available in repos)"
+        if run $MGR_ADD kubectl 2>/dev/null; then
+            ok "kubectl installed"
+        else
+            warn "kubectl not available in default repos; skipping (install manually if needed)."
+        fi
     fi
 }