feat(m9): add CSV export for contract-sn report

services/delivery-platform-api/src/main/java/cn/craftlabs/platform/api/report/ReportController.java

@@ -4,11 +4,18 @@ import cn.craftlabs.platform.api.service.ReportService;
 import cn.craftlabs.platform.api.web.dto.CallbackStatsResponse;
 import cn.craftlabs.platform.api.web.dto.ContractSnReportRow;
 import cn.craftlabs.platform.api.web.dto.ProjectHealthRow;
+import org.springframework.core.io.ByteArrayResource;
+import org.springframework.core.io.Resource;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
+import java.nio.charset.StandardCharsets;
+import java.time.LocalDate;
 import java.util.List;
 
 @RestController
@@ -39,4 +46,27 @@ public class ReportController {
     public List<ProjectHealthRow> getProjectHealth() {
         return reportService.getProjectHealth();
     }
+
+    @GetMapping("/export")
+    public ResponseEntity<Resource> exportReport(
+            @RequestParam String type,
+            @RequestParam(required = false) Long projectId,
+            @RequestParam(required = false) Long contractId) {
+
+        String csv = reportService.exportReport(type, projectId, contractId);
+
+        byte[] bytes = csv.getBytes(StandardCharsets.UTF_8);
+        byte[] bom = {(byte) 0xEF, (byte) 0xBB, (byte) 0xBF};
+        byte[] withBom = new byte[bom.length + bytes.length];
+        System.arraycopy(bom, 0, withBom, 0, bom.length);
+        System.arraycopy(bytes, 0, withBom, bom.length, bytes.length);
+
+        ByteArrayResource resource = new ByteArrayResource(withBom);
+
+        return ResponseEntity.ok()
+                .header(HttpHeaders.CONTENT_DISPOSITION,
+                        "attachment; filename=report-" + type + "-" + LocalDate.now() + ".csv")
+                .contentType(MediaType.parseMediaType("text/csv; charset=utf-8"))
+                .body(resource);
+    }
 }

services/delivery-platform-api/src/main/java/cn/craftlabs/platform/api/service/ReportService.java

@@ -162,6 +162,35 @@ public class ReportService {
         }).collect(Collectors.toList());
     }
 
+    public String exportReport(String type, Long projectId, Long contractId) {
+        StringBuilder sb = new StringBuilder();
+
+        if ("contract-sn".equals(type)) {
+            sb.append("合同名称,客户,行项,应发,实发,已激活,缺口,状态\n");
+            List<ContractSnReportRow> rows = getContractSnReport(projectId, contractId);
+            for (ContractSnReportRow r : rows) {
+                sb.append(escapeCsv(r.getContractTitle())).append(",");
+                sb.append(escapeCsv(r.getCustomerName())).append(",");
+                sb.append(escapeCsv(r.getLineItemName())).append(",");
+                sb.append(r.getExpectedCount()).append(",");
+                sb.append(r.getIssuedCount()).append(",");
+                sb.append(r.getActivatedCount()).append(",");
+                sb.append(r.getGapCount()).append(",");
+                sb.append(escapeCsv(r.getStatus())).append("\n");
+            }
+        }
+
+        return sb.toString();
+    }
+
+    private String escapeCsv(String value) {
+        if (value == null) return "";
+        if (value.contains(",") || value.contains("\"") || value.contains("\n")) {
+            return "\"" + value.replace("\"", "\"\"") + "\"";
+        }
+        return value;
+    }
+
     private String resolveCustomerName(Long customerId) {
         if (customerId == null) {
             return null;