feat: improve Claude binary detection for active NVM environments

[junis84]

🎯 Problem

Currently, Claudia may not properly detect Claude binaries installed through NVM (Node Version Manager) when users have multiple Node.js versions installed. This can lead to:

• Wrong Claude version being selected
• Claude not found errors despite being installed
• Inconsistent behavior across different NVM environments

🔧 Solution

This PR enhances the Claude binary detection logic by:

Key Changes:

• Added NVM_BIN environment variable detection - Prioritizes the currently active NVM environment
• Improved priority system - Places nvm-active installations at priority level 4 (just before other NVM versions)
• Consolidated NVM logic - All NVM-related detection now happens in find_nvm_installations()
• Maintained backward compatibility - No breaking changes to existing functionality

Technical Details:

// New: Check NVM_BIN environment variable first
if let Ok(nvm_bin) = std::env::var("NVM_BIN") {
    let claude_path = PathBuf::from(&nvm_bin).join("claude");
    // ... detect Claude in active NVM environment
}

[tebayoso]

Check #3 is not just detecting the nvm, you need to add the selector.

[movax01h]

Hi there! Seems I create a duplicate PR #61
Its working for me right now, decline it if you don't need it.