Generate comprehensive technical architecture documentation with Mermaid diagrams

[Copilot]

This PR creates comprehensive technical architecture documentation for the Jan AI assistant project, providing detailed visual documentation with Mermaid diagrams to help developers understand the system's design and implementation.

Documentation Added

1. Technical Architecture Overview (/docs/architecture)

A comprehensive overview of Jan's architecture including:

• High-level system architecture showing the React frontend, Tauri runtime, AI engines, and storage layers
• Core module structure with detailed TypeScript type organization across 11 categories (API, assistant, config, engine, etc.)
• Extension system architecture demonstrating the plugin-based approach with lifecycle management
• Data flow patterns showing how user interactions flow through the system to AI processing
• Deployment architecture covering Windows, macOS, and Linux packaging and distribution

2. Developer Architecture Guide (/docs/developer-architecture)

Advanced architectural patterns for developers including:

• Event-driven architecture with message routing and reactive updates
• Dependency injection patterns for service management and testability
• Inter-process communication flows between React frontend and Rust backend
• State management strategies combining global application state with local component state
• Multi-layered security architecture with sandboxing and privacy protection
• Performance optimization techniques including caching, resource pooling, and monitoring

3. API Architecture Reference (/docs/api-architecture)

Complete API documentation covering:

• Multi-layered API architecture with external REST, internal Tauri commands, and system APIs
• Detailed Tauri command categorization (filesystem, application, extension, system, server, MCP, threads, downloads)
• Extension API surface with lifecycle hooks and service integration patterns
• REST API server implementation with OpenAI-compatible endpoints
• Comprehensive security model with authentication, validation, and error handling
• Performance optimization strategies including caching, batching, and resource management

4. Infrastructure & Deployment (/docs/infrastructure-architecture)

Infrastructure and deployment patterns including:

• Build system architecture with Makefile orchestration and Yarn workspaces
• Cross-platform runtime environment showing process architecture and GPU utilization
• Cloud integration patterns while maintaining privacy-first principles
• Hardware scaling strategies from minimum (8GB RAM) to high-end (64GB+ RAM) configurations
• Complete development workflow including testing strategies and CI/CD pipelines

Key Features

• 40+ detailed Mermaid diagrams visualizing system relationships, data flows, and architectural patterns
• Complete component mapping across all system layers from UI to storage
• Security-first documentation highlighting Jan's privacy-preserving local-first architecture
• Performance guidance with optimization strategies for different hardware configurations
• Developer onboarding materials for understanding and extending the codebase
• Cross-platform deployment strategies and packaging approaches

The documentation leverages the existing Mermaid integration in Jan's Nextra-based docs site and has been validated to build successfully. This provides a solid foundation for developers to understand, contribute to, and extend the Jan AI assistant platform.

Fixes #1.

Warning

Firewall rules blocked me from connecting to one or more addresses (expand for details)

I tried to connect to the following addresses, but was blocked by firewall rules:

• https://api.github.com/repos/menloresearch/jan
  • Triggering command: REDACTED, pid is -1 (http block)
• https://api.github.com/repos/menloresearch/jan/releases
  • Triggering command: REDACTED, pid is -1 (http block)
• https://api.github.com/repos/menloresearch/jan/releases/latest
  • Triggering command: REDACTED, pid is -1 (http block)

If you need me to access, download, or install something from one of these locations, you can either:

• Configure Actions setup steps to set up my environment, which run before the firewall is enabled
• Add the appropriate URLs or hosts to the custom allowlist in this repository's Copilot coding agent settings (admins only)

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.

[Copilot]

@drzo 👋 This repository doesn't have Copilot instructions. With Copilot instructions, I can understand the repository better, work faster and produce higher quality PRs.

I can generate a .github/copilot-instructions.md file for you automatically. Click here to open a pre-filled issue and assign it to me. I'll write the instructions, and then tag you for review.