Enhance sample data download functionality and improve UI interaction

- Replaced direct download links with buttons for sample data downloads, improving user experience and interaction.
- Implemented event listeners for the new download buttons to handle fiscal period parameters dynamically.
- Updated the WorkbookTemplateService to include row data in the generated Excel files.
- Added integration tests to verify that the correct fiscal period is used when downloading sample data.

client/nexacro-deploy/assets/app.js

@@ -434,9 +434,9 @@ function renderUploads() {
       <div class="row actions">
         <button data-action="upload" ${isOperator() ? "" : "disabled"}>파일 업로드</button>
         <button class="secondary" data-action="reload-uploads">내역 새로고침</button>
-        <a class="ghost" href="/sample-data/trial-balance-invalid.xlsx" download>오류 샘플</a>
+        <button class="ghost" data-action="download-sample" data-sample-code="trial-balance-invalid">오류 샘플</button>
-        <a class="ghost" href="/sample-data/trial-balance-valid.xlsx" download>정상 TB</a>
+        <button class="ghost" data-action="download-sample" data-sample-code="trial-balance-valid">정상 TB</button>
-        <a class="ghost" href="/sample-data/forecast-valid.xlsx" download>정상 Forecast</a>
+        <button class="ghost" data-action="download-sample" data-sample-code="forecast-valid">정상 Forecast</button>
       </div>
     </div>
     <div class="panel">
@@ -604,14 +604,6 @@ function shellContent(content) {
         </div>
       </aside>
       <main class="main">
-        <div class="topbar">
-          <div></div>
-          <div class="footer-links">
-            <a href="/sample-data/trial-balance-invalid.xlsx" download>오류 샘플</a>
-            <a href="/sample-data/trial-balance-valid.xlsx" download>정상 TB</a>
-            <a href="/sample-data/forecast-valid.xlsx" download>정상 Forecast</a>
-          </div>
-        </div>
         ${content}
       </main>
     </div>
@@ -836,6 +828,14 @@ function bindEvents() {
     });
   }
 
+  document.querySelectorAll("[data-action='download-sample']").forEach((button) => {
+    button.addEventListener("click", () => {
+      const fiscalPeriod = document.getElementById("upload-period")?.value?.trim() || "2026-03";
+      const sampleCode = button.dataset.sampleCode;
+      window.location.href = `/api/uploads/samples/${sampleCode}/download?fiscalPeriod=${encodeURIComponent(fiscalPeriod)}`;
+    });
+  });
+
   document.querySelectorAll("[data-action='delete-upload']").forEach((button) => {
     button.addEventListener("click", async () => {
       if (!isOperator()) {

server/api/src/main/java/com/hanwha/nexacrodemo/upload/WorkbookTemplateService.java

@@ -77,6 +77,13 @@ public class WorkbookTemplateService {
             for (int index = 0; index < headers.size(); index++) {
                 header.createCell(index).setCellValue(headers.get(index));
             }
+            int rowIndex = 1;
+            for (List<String> rowValues : rows) {
+                Row row = dataSheet.createRow(rowIndex++);
+                for (int cellIndex = 0; cellIndex < rowValues.size(); cellIndex++) {
+                    row.createCell(cellIndex).setCellValue(rowValues.get(cellIndex));
+                }
+            }
 
             ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
             workbook.write(outputStream);

server/api/src/test/java/com/hanwha/nexacrodemo/upload/UploadValidationIntegrationTest.java

@@ -7,7 +7,9 @@ import static org.springframework.test.web.servlet.request.MockMvcRequestBuilder
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
+import java.io.ByteArrayInputStream;
 import org.junit.jupiter.api.Test;
+import org.apache.poi.ss.usermodel.WorkbookFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
 import org.springframework.boot.test.context.SpringBootTest;
@@ -111,6 +113,23 @@ class UploadValidationIntegrationTest {
             .andExpect(status().isForbidden());
     }
 
+    @Test
+    void sampleDownloadUsesRequestedFiscalPeriod() throws Exception {
+        MockHttpSession session = login("viewer", "demo1234");
+
+        MvcResult result = mockMvc.perform(get("/api/uploads/samples/trial-balance-valid/download")
+                .param("fiscalPeriod", "2026-04")
+                .session(session))
+            .andExpect(status().isOk())
+            .andReturn();
+
+        try (var workbook = WorkbookFactory.create(new ByteArrayInputStream(result.getResponse().getContentAsByteArray()))) {
+            var dataSheet = workbook.getSheet("DATA");
+            var firstDataRow = dataSheet.getRow(1);
+            org.junit.jupiter.api.Assertions.assertEquals("2026-04", firstDataRow.getCell(0).getStringCellValue());
+        }
+    }
+
     private MockHttpSession login(String username, String password) throws Exception {
         MvcResult result = mockMvc.perform(post("/api/auth/login")
                 .contentType(MediaType.APPLICATION_JSON)

templates/nexacro/preview-app.js.tpl

@@ -760,6 +760,14 @@ function bindEvents() {
     });
   }
 
+  document.querySelectorAll("[data-action='download-sample']").forEach((button) => {
+    button.addEventListener("click", () => {
+      const fiscalPeriod = document.getElementById("upload-period")?.value?.trim() || "2026-03";
+      const sampleCode = button.dataset.sampleCode;
+      window.location.href = `/api/uploads/samples/${sampleCode}/download?fiscalPeriod=${encodeURIComponent(fiscalPeriod)}`;
+    });
+  });
+
   document.querySelectorAll("[data-action='delete-upload']").forEach((button) => {
     button.addEventListener("click", async () => {
       if (!isOperator()) {