fix: MediaType 命名冲突和 getAuthorization 参数类型

- okhttp3.MediaType 和 SDK MediaType 冲突，改用全限定名
- getAuthorization 需要 URI 参数而非 String

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

service/src/main/java/com/kym/service/wechat/impl/WechatPayFapiaoService.java

@@ -132,14 +132,14 @@ public class WechatPayFapiaoService {
         okhttp3.RequestBody multipartBody = new MultipartBody.Builder(boundary)
                 .setType(MultipartBody.FORM)
                 .addFormDataPart("meta", null,
-                        okhttp3.RequestBody.create(meta, MediaType.parse("application/json")))
+                        okhttp3.RequestBody.create(meta, okhttp3.MediaType.parse("application/json")))
                 .addFormDataPart("file", "invoice.pdf",
-                        okhttp3.RequestBody.create(pdfBytes, MediaType.parse("application/pdf")))
+                        okhttp3.RequestBody.create(pdfBytes, okhttp3.MediaType.parse("application/pdf")))
                 .build();
 
         // 用 SDK 生成签名 — 签名的 body 是 meta 字符串
         String auth = WxPayServiceImpl.config.createCredential()
-                .getAuthorization(url, "POST", meta);
+                .getAuthorization(new java.net.URI(url), "POST", meta);
 
         // 发送请求
         okhttp3.Request request = new Request.Builder()