Prototype with single host server and no admin panel (#2)

Reviewed-on: wrenn/sandbox#2
Co-authored-by: pptx704 <rafeed@omukk.dev>
Co-committed-by: pptx704 <rafeed@omukk.dev>

envd/internal/api/error.go

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: Apache-2.0
+
+package api
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+)
+
+func jsonError(w http.ResponseWriter, code int, err error) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+
+	w.WriteHeader(code)
+	encodeErr := json.NewEncoder(w).Encode(Error{
+		Code:    code,
+		Message: err.Error(),
+	})
+	if encodeErr != nil {
+		http.Error(w, errors.Join(encodeErr, err).Error(), http.StatusInternalServerError)
+	}
+}