Preserve security configurations

Always respect explicitly set security attributes and properly sanitize user inputs to prevent security vulnerabilities. When modifying security-related configurations:

1. Only apply default values when the attribute is not explicitly set
2. Thoroughly validate and sanitize URL paths and other user inputs to prevent path traversal attacks

Example 1: When handling cookie security attributes:

// Good: Only override SameSite when not explicitly set
if cookie.SameSite == http.SameSiteDefaultMode {
    cookie.SameSite = c.sameSite
}

// Bad: Unconditionally overriding security attributes
cookie.SameSite = c.sameSite

Example 2: For URL path sanitization:

// Good: Initialize regex patterns once, outside of functions
var pathSanitizer = regexp.MustCompile("[^a-zA-Z0-9/-]+")

// Use the pre-compiled pattern to sanitize paths
sanitizedPath := pathSanitizer.ReplaceAllString(path, "")

Properly preserving security configurations and sanitizing inputs helps prevent CSRF, XSS, and path traversal vulnerabilities.