Function detect_browsers 

pub fn detect_browsers() -> Vec<BrowserInfo>

Detect installed browsers on the current OS.

This function never errors: it returns an empty list when nothing is detected.

Detection sources (best-effort):

• Windows: common install paths + .exe version info
• macOS: /Applications/*.app + Info.plist version
• Linux: PATH binaries + Flatpak/Snap inspection (if available)