fix(rest): format history length query parameter for v0.3

Apply the same single-digit formatting fix to RestTransport_v0_3, whose getTask still used %2d and padded single-digit history lengths with a leading space, producing an invalid query parameter such as historyLength= 5. Add a regression test using a single-digit history length.

This fixes a2aproject#1197

Author: 014-code

compat-0.3/client/transport/rest/src/main/java/org/a2aproject/sdk/compat03/client/transport/rest/RestTransport_v0_3.java

@@ -140,7 +140,7 @@ public Task_v0_3 getTask(TaskQueryParams_v0_3 taskQueryParams, @Nullable ClientC
         try {
             String url;
             if (taskQueryParams.historyLength() > 0) {
-                url = agentUrl + String.format("/v1/tasks/%1s?historyLength=%2d", taskQueryParams.id(), taskQueryParams.historyLength());
+                url = agentUrl + String.format("/v1/tasks/%s?historyLength=%d", taskQueryParams.id(), taskQueryParams.historyLength());
             } else {
                 url = agentUrl + String.format("/v1/tasks/%1s", taskQueryParams.id());
             }

compat-0.3/client/transport/rest/src/test/java/org/a2aproject/sdk/compat03/client/transport/rest/RestTransport_v0_3_Test.java

@@ -188,14 +188,15 @@ public void testGetTask() throws Exception {
                 request()
                         .withMethod("GET")
                         .withPath("/v1/tasks/de38c76d-d54c-436c-8b9f-4c2703648d64")
+                        .withQueryStringParameter("historyLength", "5")
         )
                 .respond(
                         response()
                                 .withStatusCode(200)
                                 .withBody(GET_TASK_TEST_RESPONSE)
                 );
         ClientCallContext_v0_3 context = null;
-        TaskQueryParams_v0_3 request = new TaskQueryParams_v0_3("de38c76d-d54c-436c-8b9f-4c2703648d64", 10);
+        TaskQueryParams_v0_3 request = new TaskQueryParams_v0_3("de38c76d-d54c-436c-8b9f-4c2703648d64", 5);
         RestTransport_v0_3 instance = new RestTransport_v0_3(CARD);
         Task_v0_3 task = instance.getTask(request, context);
         assertEquals("de38c76d-d54c-436c-8b9f-4c2703648d64", task.id());