D-51: Implement Plugin Marketplace

[Nanle-code]

Create a centralized plugin marketplace similar to VS Code extensions or npm packages, allowing developers to discover, install, and manage StarForge plugins with ratings, reviews, and automatic updates.

Proposed Changes:

• Design plugin marketplace API
• Implement plugin discovery and search
• Add plugin rating and review system
• Create plugin versioning and updates
• Implement plugin dependency management
• Add plugin security verification
• Create web interface for plugin browsing

Acceptance Criteria:

• Plugin marketplace API works
• Plugin discovery and search functional
• Rating and review system
• Automatic plugin updates
• Dependency management
• Security verification
• Web interface available

Priority: High
Complexity: Large
Labels: enhancement, marketplace, plugins