feat: [#31] Add comprehensive deployment stages and workflow documentation

- Document complete two-phase deployment architecture
- Phase 1: Build external artifacts (Docker images, golden VM images)
- Phase 2: Environment-specific provisioning and deployment
- Include detailed stage definitions, workflows, and automation status
- Add error handling strategies and rollback procedures
- Define performance optimization patterns for development/testing/production
- Establish foundation for PoC-to-production redesign implementation

Resolves requirements for deployment stage documentation in project redesign.

Author: josecelano

docs/redesign/phase1-requirements/deployment-stages-and-workflow.md

@@ -0,0 +1,306 @@
+# Deployment Stages and Workflow
+
+## Overview
+
+This document defines the complete deployment workflow for Torrust Tracker environments,
+breaking down the process into discrete stages that can be executed independently or
+as part of an automated pipeline.
+
+The workflow separates concerns between external artifact preparation, infrastructure
+provisioning, and application deployment to enable efficient iteration and debugging.
+
+## Stage Classification
+
+**Generic Stages**: Execute once and apply to all environments
+**Environment-Specific Stages**: Execute per environment with environment-specific configuration
+
+## Complete Deployment Workflow
+
+### Phase 1: Build External Artifacts (Generic)
+
+These stages prepare reusable artifacts that can be deployed to any environment.
+
+#### 1.1 Generate Tracker Docker Image
+
+**Purpose**: Create the application container image using twelve-factor build principles.
+
+**Execution Method**: Automated via CI/CD pipeline
+
+**Trigger**: New tag creation in the Torrust Tracker repository
+
+**Output**: Docker image tagged and pushed to registry (e.g., Docker Hub)
+
+**Environment Integration**:
+
+- Docker image tag becomes an input variable for environment configuration
+- Different environments can use different image versions (e.g., `latest` for
+  development, `v1.2.3` for production)
+
+**Automation Status**: ✅ Fully automated
+
+**Example Tags**:
+**Expected Outputs**:
+
+- `torrust/torrust-tracker:latest` - Latest development build
+- `torrust/torrust-tracker:v1.2.3` - Tagged release build
+- `torrust/torrust-tracker:staging` - Staging environment build
+
+**Automation Level**: Fully automated through CI/CD (triggered by git tag creation)
+
+#### 1.2 Generate Golden VM Image
+
+**Purpose**: Create base virtual machine image with pre-installed system dependencies.
+
+**Execution Method**: Manual process with scripted automation
+
+**Trigger**: System dependency updates (infrequent)
+
+**Output**: VM image/ISO with pre-configured base system
+
+**Contents**:
+
+- Base operating system (Ubuntu 24.04 LTS)
+- Docker and Docker Compose (current stable versions)
+- System dependencies and security updates
+- Performance optimizations and system tuning
+
+**Update Frequency**:
+
+- **Rarely** - Only when updating fundamental system components
+- Typically 2-4 times per year or for security patches
+
+**Automation Status**: 🔄 Semi-automated (manual trigger, scripted execution)
+
+**Benefits**:
+
+- Faster environment provisioning (pre-installed dependencies)
+- Consistent base system across all environments
+- Reduced network bandwidth during deployment
+- Improved security posture with pre-hardened images
+
+### Phase 2: Environment Provisioning + Application Deployment (Environment-Specific)
+
+These stages execute for each individual environment with environment-specific configuration.
+
+#### 2.1 Infrastructure Provisioning
+
+**Purpose**: Create and configure the infrastructure resources needed for the environment.
+
+**Stages**:
+
+1. **Initialize**: Prepare infrastructure automation tools and validate configuration
+
+   - Terraform/OpenTofu initialization
+   - Provider authentication verification
+   - Configuration validation and syntax checking
+
+2. **Plan**: Generate execution plan showing what resources will be created/modified
+
+   - Resource dependency analysis
+   - Cost estimation (for cloud providers)
+   - Change impact assessment
+   - Security configuration review
+
+3. **Apply**: Create the actual infrastructure resources
+   - Virtual machine provisioning
+   - Network configuration and firewall rules
+   - Storage allocation and backup setup
+   - DNS record creation (if applicable)
+
+**Environment Variables**: Provider context, resource specifications, regional settings
+
+**Output**: Running virtual machine with base system ready for application deployment
+
+**Idempotency**: Can be re-executed safely; only applies necessary changes
+
+#### 2.2 Application Deployment
+
+**Purpose**: Install and configure the Torrust Tracker application on provisioned infrastructure.
+
+**Execution Method**: Automated deployment scripts
+
+**Process**:
+
+- Application repository checkout/update
+- Environment-specific configuration generation
+- Docker Compose service orchestration
+- Service startup and dependency resolution
+
+**Input Dependencies**:
+
+- Provisioned virtual machine from stage 2.1
+- Docker image from stage 1.1
+- Environment-specific configuration
+
+**Output**: Running Torrust Tracker with all supporting services
+
+**Services Deployed**:
+
+- Torrust Tracker (HTTP/UDP endpoints)
+- MySQL database with schema initialization
+- Nginx reverse proxy with SSL configuration
+- Prometheus metrics collection
+- Grafana monitoring dashboards
+
+#### 2.3 Post-Deployment Configuration
+
+**Purpose**: Complete environment setup with additional configuration and validation.
+
+**Substages**:
+
+1. **Extra Configuration**
+
+   - SSL certificate generation/installation
+   - Domain-specific configuration
+   - Backup automation setup
+   - Monitoring alert configuration
+
+2. **Health Checks**
+
+   - Service connectivity validation
+   - API endpoint testing
+   - Database connectivity verification
+   - SSL certificate validation
+
+3. **End-to-End Testing**
+   - Complete tracker functionality validation
+   - Performance benchmarking
+   - Security configuration verification
+   - Integration testing with external systems
+
+**Execution Types**:
+
+- **Automated**: Health checks, basic connectivity tests
+- **Semi-automated**: SSL certificates (scripts with manual verification)
+- **Manual**: Advanced security configuration, performance tuning
+
+## Workflow Execution Patterns
+
+### Development Workflow
+
+```text
+[Phase 1] → [Phase 2.1] → [Phase 2.2] → [Phase 2.3]
+   ↓           ↓           ↓           ↓
+Skip        Quick        Fast        Basic
+(use latest) provision   deploy     validation
+```
+
+**Optimization**: Skip Phase 1 (use existing images), focus on rapid iteration
+
+### Staging Workflow
+
+```text
+[Phase 1] → [Phase 2.1] → [Phase 2.2] → [Phase 2.3]
+   ↓           ↓           ↓           ↓
+Specific    Production   Complete    Full
+tag/version  specs       deploy      testing
+```
+
+**Focus**: Production-like configuration with comprehensive testing
+
+### Production Workflow
+
+```text
+[Phase 1] → [Phase 2.1] → [Phase 2.2] → [Phase 2.3]
+   ↓           ↓           ↓           ↓
+Release     High-avail   Blue/green  Extensive
+version     infrastructure deployment validation
+```
+
+**Emphasis**: Maximum reliability, security, and validation
+
+## Stage Dependencies
+
+### Sequential Dependencies
+
+- **Phase 2.1** → **Phase 2.2**: Infrastructure must exist before application deployment
+- **Phase 2.2** → **Phase 2.3**: Application must be running before post-deployment configuration
+
+### Input Dependencies
+
+- **Phase 2.2** requires Docker image from **Phase 1.1**
+- **Phase 2.1** may use golden image from **Phase 1.2** (optional optimization)
+- **Phase 2.3** requires services from **Phase 2.2** to be healthy
+
+### Parallel Execution Opportunities
+
+- **Phase 1.1** and **Phase 1.2** can execute independently
+- Multiple **Phase 2** workflows can execute simultaneously for different environments
+- Within **Phase 2.3**, some configurations can be parallelized
+
+## Error Handling and Recovery
+
+### Stage Failure Recovery
+
+**Phase 1 Failures**:
+
+- Image build failures → Fix source code/dependencies, retry build
+- Golden image failures → Debug system configuration, manual intervention
+
+**Phase 2.1 Failures**:
+
+- Infrastructure errors → Review provider quotas, fix configuration, retry
+- Network/DNS issues → Verify provider settings, update configuration
+
+**Phase 2.2 Failures**:
+
+- Application startup → Check service dependencies, review logs, retry deployment
+- Configuration errors → Validate environment settings, fix templates
+
+**Phase 2.3 Failures**:
+
+- SSL certificate issues → Debug DNS/domain configuration, manual intervention
+- Health check failures → Investigate service status, review network connectivity
+
+### Rollback Strategies
+
+**Infrastructure Rollback**:
+
+- Terraform/OpenTofu state management for resource cleanup
+- Snapshot restoration for critical data preservation
+
+**Application Rollback**:
+
+- Previous Docker image deployment
+- Configuration version restoration
+- Database migration reversal (if applicable)
+
+## Performance Optimization
+
+### Stage Parallelization
+
+**Development Environments**:
+
+- Multiple developers can provision simultaneously
+- Shared golden images reduce provision time
+- Local caching of Docker images
+
+**CI/CD Pipeline**:
+
+- Parallel environment provisioning for different test suites
+- Artifact caching between stages
+- Resource pooling for temporary environments
+
+### Resource Management
+
+**Infrastructure Efficiency**:
+
+- Shared provider contexts for cost optimization
+- Resource scheduling for non-production environments
+- Automatic cleanup of temporary/expired environments
+
+**Application Optimization**:
+
+- Docker layer caching
+- Configuration template pre-processing
+- Health check optimization for faster validation
+
+## Related Documentation
+
+- [Core Concepts and Terminology](core-concepts-and-terminology.md) - Fundamental definitions
+- [Three-Phase Deployment Architecture](three-phase-deployment-architecture.md) - Architectural principles
+- [Environment Configuration Management](environment-configuration-management.md) - Configuration handling
+
+## Revision History
+
+- **v1.0** - Initial deployment workflow definition based on PoC implementation analysis