Add better documentation and scripts for air-gapped deployment

Created new helper scripts:
- quickstart-airgap.sh: One-command deployment for restricted environments
- check-ready.sh: Validates that pre-built files exist before deployment

Updated documentation:
- Enhanced Dockerfile.frontend.prebuilt with clearer error messages
- Updated DEPLOYMENT.md with step-by-step quick start guide
- Updated README.md to distinguish standard vs air-gapped deployment

Key improvements:
- Clear warning that build must happen BEFORE docker-compose
- Helper script that combines build + deployment steps
- Readiness check to catch missing pre-built files early
- Better instructions for test environments with restricted npm access

This addresses the common error where Docker fails because
frontend/dist/frontend/browser doesn't exist yet.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

quickstart-airgap.sh

@@ -0,0 +1,75 @@
+#!/bin/bash
+
+set -e
+
+echo "========================================="
+echo "Warehouse13 - Air-Gapped Quick Start"
+echo "========================================="
+echo ""
+echo "This script is for restricted/air-gapped environments"
+echo "where npm packages cannot be downloaded during Docker build."
+echo ""
+
+# Check if we're in the right directory
+if [ ! -f "docker-compose.yml" ]; then
+    echo "Error: Must run from project root directory"
+    exit 1
+fi
+
+# Check if Docker is installed
+if ! command -v docker &> /dev/null; then
+    echo "Error: Docker is not installed. Please install Docker first."
+    exit 1
+fi
+
+# Check if Docker Compose is installed
+if ! command -v docker-compose &> /dev/null; then
+    echo "Error: Docker Compose is not installed. Please install Docker Compose first."
+    exit 1
+fi
+
+echo "Step 1: Building Angular frontend locally..."
+echo "==========================================="
+./build-for-airgap.sh
+
+echo ""
+echo "Step 2: Starting Docker containers..."
+echo "==========================================="
+docker-compose up -d --build
+
+echo ""
+echo "Step 3: Waiting for services to be ready..."
+sleep 15
+
+echo ""
+echo "========================================="
+echo "Services are running!"
+echo "========================================="
+echo ""
+echo "Frontend:         http://localhost:4200"
+echo "API:              http://localhost:8000"
+echo "API Docs:         http://localhost:8000/docs"
+echo "MinIO Console:    http://localhost:9001"
+echo "  Username: minioadmin"
+echo "  Password: minioadmin"
+echo ""
+echo "To view logs:     docker-compose logs -f"
+echo "To stop:          docker-compose down"
+echo ""
+echo "========================================="
+echo "Testing the API..."
+echo "========================================="
+
+# Wait a bit more for API to be fully ready
+sleep 5
+
+# Test health endpoint
+if curl -s http://localhost:8000/health | grep -q "healthy"; then
+    echo "✓ API is healthy!"
+    echo ""
+    echo "========================================="
+    echo "Setup complete! 🚀"
+    echo "========================================="
+else
+    echo "⚠ API is not responding yet. Please wait a moment and check http://localhost:8000/health"
+fi