Skip required-packages step on re-run

On second run, is_installed base (command -v ncdu) detects that base
packages are already present and jumps straight to the service menu,
skipping the required-setup banner, confirm prompt, and apt-get install.
The first-run path is unchanged; `sudo ./setup.sh base` forces reinstall.

https://claude.ai/code/session_01Y4dMKtkqkpvmgDKoRdzhTG

setup.sh

@@ -152,10 +152,23 @@ fi
 # ── Guided interactive flow ──────────────────────────────────────────────────
 require_root
 
-# 1) Show the REQUIRED set and let the user cancel before anything happens.
+_VER="$(cat "$HERE/VERSION" 2>/dev/null || echo '?')"
+
+if is_installed base; then
+    # ── Re-run: base already present — skip required step ────────────────────
     echo ""
     echo "╔══════════════════════════════════════════════════════════════╗"
-echo "║  Ubuntu Post-Install  ·  v$(cat "$HERE/VERSION" 2>/dev/null || echo '?')"
+    echo "║  Ubuntu Post-Install  ·  v${_VER}"
+    echo "╚══════════════════════════════════════════════════════════════╝"
+    echo ""
+    echo "  Base packages already installed — skipping required setup."
+    echo "  Use 'sudo ./setup.sh base' to force a reinstall."
+    echo ""
+else
+    # ── First run: show required banner, confirm, install ────────────────────
+    echo ""
+    echo "╔══════════════════════════════════════════════════════════════╗"
+    echo "║  Ubuntu Post-Install  ·  v${_VER}"
     echo "╚══════════════════════════════════════════════════════════════╝"
     echo ""
     echo "REQUIRED (installed/verified first):"
@@ -172,12 +185,12 @@ if [ "$PROCEED" != "y" ] && [ "$PROCEED" != "Y" ]; then
         exit 0
     fi
 
-# 2) Run required.
     run_service base
     if ! command -v docker >/dev/null 2>&1; then
         log_warning "Docker is not installed. Containerized services need it."
         echo "  Install with:  curl -fsSL https://get.docker.com | sh"
     fi
+fi
 
 # 3) Offer site defaults wizard if .config has no SITE_TZ yet (first run).
 if ! grep -q '^SITE_TZ=' "$DOCKER_DIR/.config" 2>/dev/null; then