Downgrade to Angular 17 with webpack for better restricted environment compatibility

- Downgrade from Angular 19 to Angular 17.3.0
- Switch from Vite-based build (@angular/build) to webpack (@angular-devkit/build-angular)
- Eliminates Vite, esbuild, and rollup dependencies that were causing issues in restricted npm environments
- Update tsconfig.json for webpack compatibility (moduleResolution: bundler)
- Update angular.json to use browser builder instead of application builder
- Update docker-compose.yml to use prebuilt Dockerfile for air-gapped deployment
- Add build-for-airgap.sh helper script for local builds
- Update DEPLOYMENT.md with Angular 17 webpack strategy notes
- Bundle size: 329.73 kB raw / 86.54 kB gzipped

This change improves compatibility with enterprise environments that have restricted package registry access.

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

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

docker-compose.yml

@@ -60,9 +60,7 @@ services:
   frontend:
     build:
       context: .
-      dockerfile: Dockerfile.frontend
-      args:
-        NPM_REGISTRY: ${NPM_REGISTRY:-https://registry.npmjs.org/}
+      dockerfile: Dockerfile.frontend.prebuilt
     ports:
       - "4200:80"
     depends_on: