style(project-apply): 调整项目申请样式优化布局

- 将项目申请表单内边距改为0取消左右填充
- 修改弹窗主体溢出控制，新增横向溢出隐藏设置
- 调整弹窗主体内边距为16px统一四周间距
- 设置弹窗背景色为浅灰色提升视觉一致性

src/views/business/project-apply.vue

@@ -1734,7 +1734,7 @@ export default {
 
 <style lang="scss" scoped>
 .project-apply-form {
-  padding: 0 8px;
+  padding: 0;
 
   :deep(.el-input),
   :deep(.el-select),
@@ -1876,7 +1876,8 @@ export default {
 :global(.project-apply-dialog .el-dialog__body) {
   max-height: 76vh;
   overflow-y: auto;
-  padding: 16px 24px 8px;
+  overflow-x: hidden;
+  padding: 16px;
   background: #f5f6fa;
 }