Migrate frontend to Angular 20 with full Docker support

Implemented a complete Angular 20 migration with modern standalone components architecture and production-ready Docker deployment:

**Frontend Migration:**
- Created Angular 20 application with standalone components (no NgModules)
- Implemented three main components: artifacts-list, upload-form, query-form
- Added TypeScript models and services for type-safe API communication
- Migrated dark theme UI with all existing features
- Configured routing and navigation between views
- Set up development proxy for seamless API integration
- Reactive forms with validation for upload and query functionality
- Auto-refresh artifacts every 5 seconds with RxJS observables
- Client-side sorting, filtering, and search capabilities
- Tags displayed as inline badges, SIM source grouping support

**Docker Integration:**
- Multi-stage Dockerfile for Angular (Node 24 build, nginx Alpine serve)
- nginx configuration for SPA routing and API proxy
- Updated docker-compose.yml with frontend service on port 80
- Health checks for all services
- Production-optimized build with gzip compression and asset caching

**Technical Stack:**
- Angular 20 with standalone components
- TypeScript for type safety
- RxJS for reactive programming
- nginx as reverse proxy
- Multi-stage Docker builds for optimal image size

All features fully functional and tested in Docker environment.

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

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

frontend/.gitignore

@@ -0,0 +1,43 @@
+# See https://docs.github.com/get-started/getting-started-with-git/ignoring-files for more about ignoring files.
+
+# Compiled output
+/dist
+/tmp
+/out-tsc
+/bazel-out
+
+# Node
+/node_modules
+npm-debug.log
+yarn-error.log
+
+# IDEs and editors
+.idea/
+.project
+.classpath
+.c9/
+*.launch
+.settings/
+*.sublime-workspace
+
+# Visual Studio Code
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+.history/*
+
+# Miscellaneous
+/.angular/cache
+.sass-cache/
+/connect.lock
+/coverage
+/libpeerconnection.log
+testem.log
+/typings
+__screenshots__/
+
+# System files
+.DS_Store
+Thumbs.db