feat: add docker support

[uprightbass360]

Docker Containerization

This implementation enables Keira3 to be deployed as a containerized web application alongside existing AzerothCore instances for database administration, while maintaining 100% backward compatibility with existing Electron functionality. I utilized claude code to help speedrun the development, but as a devops dev and a 10 year c# engineer I was able to wire together something I hope you are happy with. Check out uprightbass360/keira3 on dockerhub for a look and https://github.com/uprightbass360/acore-compose for an integrated version. I am going to be using this at home. Thank you for your hard work!

Core Architecture

Hybrid Database Connection System

• Electron Environment: Direct mysql2 connections (preserved, unchanged)
• Docker/Web Environment: HTTP API proxy with connection pooling (new)
• Automatic environment detection and transparent interface

Multi-Service Container Architecture

• Angular Frontend (nginx, port 8080)
• Database API Service (Node.js/Express, port 3001)
• External MySQL Database connectivity
• Reverse proxy integration with security and performance optimization

Complete Implementation (63 files, 12,042 additions)

Core Docker Infrastructure

• Multi-stage Dockerfile with production optimizations
• Docker Compose configurations for various deployment scenarios
• Complete environment variable management and templates
• Production-grade startup orchestration scripts

Database API Service (646 lines)

• Express.js REST API with comprehensive MySQL2 connection pooling
• HTTP endpoints: /api/database/connect, /api/database/query, /api/database/state
• Error handling with proper HTTP status codes and categorization
• Request validation, sanitization, and security measures
• Graceful shutdown handling and resource cleanup

Enhanced MysqlService Integration

• Environment-aware dual implementation (Electron + Docker)
• Transparent API interface - same functionality across all environments
• Connection pooling and performance optimizations
• Error handling and retry mechanisms

Comprehensive Testing Suite (1,394 lines)

• Unit Tests: Core API service functionality (361 lines)
• Integration Tests: End-to-end API endpoints (588 lines)
• Connection Pool Tests: Database connectivity and lifecycle (445 lines)
• Docker-specific Jest configuration and test environment
• Coverage reporting and CI/CD integration

Production Security & Performance

• nginx reverse proxy with security headers and CORS configuration
• Non-root container execution with dedicated user accounts
• Resource limits, health monitoring, and graceful shutdown
• Multi-platform builds (AMD64/ARM64) and registry support

CI/CD & Deployment Automation

• Complete GitHub Actions workflow for Docker builds and deployment
• Multi-registry support (GitHub Container Registry + DockerHub)
• Automated testing, security scanning, and health validation
• Manual workflow dispatch with environment selection
• Container health check fixes (IPv6/IPv4 localhost resolution)

Key Features Delivered

AzerothCore Integration Ready

• External MySQL database connectivity for existing AC instances
• Web-based administration interface accessible from any device
• Seamless integration with existing Docker infrastructure
• Production-grade deployment with monitoring and scaling

Developer Experience

• Zero breaking changes to existing Electron functionality
• Comprehensive documentation and deployment guides
• Enhanced testing framework with full coverage
• Modern CI/CD pipelines with automated workflows

Enterprise Production Ready

• Security hardened containers with best practices
• Resource management and performance optimization
• Health monitoring and observability integration
• Horizontal scaling and load balancing support

Files Added/Modified

Docker Infrastructure

• docker/Dockerfile, docker-compose.yml, .dockerignore
• docker/api/database-api.js, database-api.types.js
• docker/config/nginx.conf, docker-start.sh
• docker/scripts/build.sh, deploy.sh
• docker/.env.example, README.md, STRUCTURE.md

Enhanced Core Services

• libs/shared/db-layer/src/mysql.service.ts (enhanced)
• libs/shared/config/src/app.config.ts (extended)
• apps/keira/src/environments/environment.docker.ts (new)

Testing & Quality Assurance

• docker/tests/ (complete test suite with Jest configuration)
• 3 comprehensive test files with full coverage
• CI/CD integration and coverage reporting

CI/CD & Automation

• .github/workflows/docker-build-deploy-dockerhub.yml
• Makefile for build automation
• Enhanced package.json with Docker dependencies

Documentation

• Complete documentation suite in docs/
• Deployment guides, architecture documentation
• Troubleshooting and configuration references

Migration & Compatibility

• 100% Backward Compatible: All existing Electron functionality preserved
• Zero Breaking Changes: Existing configs and workflows continue unchanged
• Additive Architecture: New Docker capabilities without modification
• Environment Detection: Automatic switching between Electron and Docker modes

Deployment Scenarios

1. Standalone Container: Simple docker run with environment variables
2. Docker Compose: Full orchestration with networking and volumes
3. AzerothCore Integration: External database connectivity for AC administration
4. Production Deployment: Multi-container scaling with load balancing

This implementation transforms Keira3 from an Electron-only desktop application
into a flexible, deployable web application while preserving all existing
functionality and adding powerful new deployment capabilities for AzerothCore
database administration.

Ready for production deployment!

[uprightbass360]

Merging requires existing changes for workflow. Closing to PR from fork master