📚 Consolidate Architecture Documentation

[sfloess]

Problem

Architecture information scattered across 20+ markdown files.

Solution

Create single ARCHITECTURE.md at root consolidating:

• System overview
• Module organization (39 modules)
• Design patterns used
• ClassLoader isolation strategy
• Thread pool management
• Security model
• Clustering approach
• Links to detailed docs

Structure

# Architecture Overview

## System Design
## Module Organization  
## Key Components
## Design Patterns
## Isolation Strategy
## Further Reading

Acceptance Criteria

• ARCHITECTURE.md created
• All key decisions documented
• Diagrams included
• Links to detailed docs
• Linked from README.md

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Priority: LOW | Documentation

[sfloess]

✅ Implemented in commit b8d7f08

Created comprehensive ARCHITECTURE.md documentation consolidating all architectural information.

Documentation (605 lines):

12 Major Sections:

1. ✅ Overview & Design Philosophy
2. ✅ Core Concepts (Application, Descriptor, Isolation)
3. ✅ System Architecture (Diagrams & Flows)
4. ✅ Module Organization (25 modules documented)
5. ✅ Security Architecture (Defense in depth)
6. ✅ Deployment Models (3 modes with comparisons)
7. ✅ Design Patterns (5 patterns with examples)
8. ✅ Extension Points (5 customization areas)
9. ✅ Performance Considerations
10. ✅ Scalability (Vertical & Horizontal)
11. ✅ Operational Concerns
12. ✅ Future Architecture

Key Features:

• ASCII architecture diagrams
• Component interaction flows
• Security threat model
• Module dependency matrix
• Extension point examples
• Performance guidelines

Benefits:

• Single source of truth
• Onboarding reference
• Design decision documentation
• Security review foundation
• Technical presentation base

All architectural concepts now documented in one comprehensive guide.