Major Feature Update: Security Framework, Auto File Detection, and Apple Silicon Support

[barrulus]

Summary

This PR introduces comprehensive improvements to the vector code retrieval system with three major feature areas:

🔒 Security-First Trust Management

• Client-side trust_remote_code management with auto-detection and user consent prompts
• Persistent approval tracking in .env files with model-specific hashing
• Cross-component consistency between indexing, querying, and remote serving
• Interactive security warnings with clear risk/benefit explanations

📁 Intelligent File Detection

• Content-based file analysis replacing hardcoded extension lists
• Automatic text file detection with binary file filtering
• Multi-encoding support for robust file processing
• Recursive directory scanning with intelligent ignore patterns

🚀 Apple Silicon GPU Support

• Metal Performance Shaders (MPS) detection and utilization
• Cross-platform GPU acceleration (CUDA + MPS + CPU fallback)
• Significant performance improvements on MacBooks with Apple Silicon

🛠 Additional Improvements

• Enhanced documentation with comprehensive security and usage guides
• Type safety improvements with Pylance compliance across codebase
• Better error handling and user feedback
• Environment configuration updates and examples

Test Plan

• Test trust_remote_code prompts with various models
• Verify automatic file detection across different repositories
• Confirm Apple Silicon GPU acceleration on MacBooks
• Validate client-server trust communication
• Test backward compatibility with existing databases

Breaking Changes

None - all changes are backward compatible with existing installations and databases.