## ADDED Requirements

### Requirement: Comprehensive Architecture Documentation

The project SHALL provide comprehensive architecture documentation that serves as both a technical reference and practical implementation guide for fsspeckit users.

#### Scenario: Users understand system design decisions

- **WHEN** a developer reads `docs/architecture.md`
- **THEN** they find Architectural Decision Records (ADRs) explaining WHY key design choices were made
- **AND** the documentation includes real implementation patterns rather than idealized descriptions
- **AND** cross-domain integration examples show how packages work together in practice.

#### Scenario: Developers implement solutions with fsspeckit

- **WHEN** a user needs to implement a data processing solution
- **THEN** the architecture documentation provides concrete integration patterns between domain packages
- **AND** includes performance optimization strategies and deployment considerations
- **AND** shows extension points for custom development.

#### Scenario: Operators deploy fsspeckit in production

- **WHEN** a DevOps engineer reviews the architecture for production deployment
- **THEN** the documentation includes multi-cloud deployment patterns
- **AND** covers security, compliance, and operational excellence practices
- **AND** provides monitoring and observability architecture guidance.

### Requirement: Architectural Decision Records

The architecture documentation SHALL include formal Architectural Decision Records (ADRs) that document critical design choices with rationale and alternatives considered.

#### Scenario: Understanding domain package architecture

- **WHEN** a reader questions why fsspeckit uses a domain package structure
- **THEN** ADR-001 documents the decision with trade-offs and alternatives considered
- **AND** explains the benefits over monolithic or other organizational approaches.

#### Scenario: Evaluating backend-neutral planning

- **WHEN** a developer examines the merge and maintenance planning architecture
- **THEN** ADR-002 documents the centralized vs. decentralized design decision
- **AND** explains why backend-neutral planning was placed in the core package.

#### Scenario: Understanding backwards compatibility strategy

- **WHEN** a user questions the utils façade pattern
- **THEN** ADR-003 documents the migration strategy and reasoning
- **AND** explains the gradual transition path for existing users.

### Requirement: Real Implementation Documentation

The architecture documentation SHALL accurately reflect the actual implementation rather than idealized or outdated descriptions.

#### Scenario: Package interaction understanding

- **WHEN** a developer examines how packages integrate
- **THEN** the documentation shows actual data flow and component interactions
- **AND** includes real code examples from the current implementation
- **AND** documents error handling patterns and resilience strategies.

#### Scenario: Performance optimization

- **WHEN** a user needs to optimize fsspeckit performance
- **THEN** the architecture documentation documents actual caching strategies
- **AND** includes parallel processing patterns with real performance characteristics
- **AND** provides monitoring and observability implementation details.

### Requirement: Visual Architecture Documentation

The architecture documentation SHALL include comprehensive visual diagrams that accurately represent the system structure and data flow.

#### Scenario: High-level architecture understanding

- **WHEN** a stakeholder needs a quick overview
- **THEN** updated Mermaid diagrams show the actual domain package structure
- **AND** component interaction diagrams illustrate real integration patterns
- **AND** deployment architecture diagrams show production configurations.

#### Scenario: Implementation detail understanding

- **WHEN** a developer examines specific integration patterns
- **THEN** detailed data flow diagrams show how packages interact in practice
- **AND** component lifecycle diagrams illustrate initialization and shutdown patterns
- **AND** extension point diagrams show where custom code can be integrated.

### Requirement: Cross-Domain Integration Examples

The architecture documentation SHALL include practical examples of how different fsspeckit packages work together to solve real problems.

#### Scenario: Learning integration patterns

- **WHEN** a developer needs to combine multiple packages
- **THEN** the documentation provides end-to-end pipeline examples
- **AND** shows cross-domain error handling and retry patterns
- **AND** demonstrates configuration and deployment best practices.

#### Scenario: Production deployment patterns

- **WHEN** an organization deploys fsspeckit at scale
- **THEN** architecture examples show multi-cloud deployment strategies
- **AND** include security and compliance implementation patterns
- **AND** demonstrate monitoring and operational excellence practices.