feat: organize documentation into logical subdirectories

✅ Created organized project documentation structure
- project/ai-economics/: AI Economics Masters documentation
- project/cli/: Command-line interface documentation
- project/infrastructure/: System infrastructure and deployment docs
- project/requirements/: Project requirements and migration docs
- project/completion/: 100% project completion summary
- project/workspace/: Workspace strategy and organization

✅ Updated MASTER_INDEX.md to reflect new organization
- Added project documentation section with detailed breakdown
- Updated navigation to include new subdirectory structure
- Maintained existing documentation hierarchy

✅ Updated project/README.md for new organization
- Complete project documentation overview
- Directory structure explanation
- Quick access guide for each subdirectory
- Links to related documentation

📊 Documentation Organization Results:
- 10 files moved into 6 logical subdirectories
- Improved navigation and discoverability
- Maintained all existing content and links
- Enhanced project documentation structure

🎯 Documentation Status: 100% Organized and Complete

docs/MASTER_INDEX.md

@@ -276,6 +276,19 @@ All external documentation accessible from main docs directory:
 | [📝 Implementation](implementation/) | Implementation details and guides | Active |
 | [🔧 Maintenance](maintenance/) | Maintenance procedures and guides | Active |
 | [👥 Project](project/) | Project information and coordination | Active |
+
+#### **📋 [Project Documentation](project/)**
+**Core project documentation and implementation guides:**
+
+| Category | Files | Content |
+|----------|-------|---------|
+| [🧠 AI Economics](project/ai-economics/) | 1 file | Advanced AI economics intelligence |
+| [💻 CLI](project/cli/) | 1 file | Command-line interface documentation |
+| [🏗️ Infrastructure](project/infrastructure/) | 4 files | System infrastructure and deployment |
+| [📋 Requirements](project/requirements/) | 2 files | Project requirements and migration |
+| [✅ Completion](project/completion/) | 1 file | 100% project completion summary |
+| [🔧 Workspace](project/workspace/) | 1 file | Workspace strategy and organization |
+
 | [📈 Summaries](summaries/) | Project summaries and reports | Active |
 | [🔄 Workflows](workflows/) | Development and operational workflows | Active |