Function authenticate 

pub async fn authenticate(
    headers: HeaderMap,
    request: Request,
    next: Next,
) -> Result<Response, (StatusCode, Json<AuthError>)>

Authentication middleware

Validates that the request includes a Bearer token in the Authorization header. This token should be a Kubernetes ServiceAccount token.

Headers

• Authorization: Bearer <token> - Required

Errors

Returns 401 Unauthorized if:

• No Authorization header is present
• Authorization header is malformed
• Token is invalid (future implementation)