feat: Introduce JSON decoding utility functions and update error handling in Claude and OpenAI response structures

common/json.go

@@ -0,0 +1,14 @@
+package common
+
+import (
+	"bytes"
+	"encoding/json"
+)
+
+func DecodeJson(data []byte, v any) error {
+	return json.NewDecoder(bytes.NewReader(data)).Decode(v)
+}
+
+func DecodeJsonStr(data string, v any) error {
+	return DecodeJson(StringToByteSlice(data), v)
+}