Add direct tests for handler core methods, template rendering, and query validation

Author: andrew

internal/handler/conan_test.go

@@ -11,7 +11,8 @@ import (
 
 func conanTestProxy() *Proxy {
 	return &Proxy{
-		Logger: slog.Default(),
+		Logger:     slog.Default(),
+		HTTPClient: http.DefaultClient,
 	}
 }