Add air-gapped deployment option for restricted environments

Added support for air-gapped and enterprise environments where npm package access is restricted, specifically addressing esbuild platform binary download issues.

**New Files:**
- Dockerfile.frontend.prebuilt: Alternative Dockerfile that uses pre-built Angular files
- DEPLOYMENT.md: Comprehensive deployment guide with two options

**Changes:**
- package.json: Added optionalDependencies for esbuild platform binaries
  - @esbuild/darwin-arm64
  - @esbuild/darwin-x64
  - @esbuild/linux-arm64
  - @esbuild/linux-x64

**Deployment Options:**

**Option 1 - Standard Build (current default):**
- Builds Angular in Docker
- Requires npm registry access
- Best for cloud/development

**Option 2 - Pre-built (for air-gapped):**
1. Build Angular locally: npm run build:prod
2. Change dockerfile in docker-compose.yml to Dockerfile.frontend.prebuilt
3. Docker only needs to copy files, no npm required
- No npm registry access needed during Docker build
- Faster, more reliable builds
- Best for enterprise/air-gapped/CI-CD

**Troubleshooting:**
See DEPLOYMENT.md for full troubleshooting guide including:
- esbuild platform binary issues
- Custom npm registry configuration
- Environment-specific recommendations

This addresses npm package access issues in restricted environments while maintaining flexibility for standard deployments.

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

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

frontend/package.json

@@ -45,5 +45,11 @@
     "karma-jasmine": "~5.1.0",
     "karma-jasmine-html-reporter": "~2.1.0",
     "typescript": "~5.8.0"
+  },
+  "optionalDependencies": {
+    "@esbuild/darwin-arm64": "^0.25.4",
+    "@esbuild/darwin-x64": "^0.25.4",
+    "@esbuild/linux-arm64": "^0.25.4",
+    "@esbuild/linux-x64": "^0.25.4"
   }
 }