feat(dialog): 聊天消息 Markdown 表格单元格强制不换行

DialogMarkdown 根节点新增 .dialog-markdown 类，统一规则放 markdown.less，删除 dialog-wrapper.scss 里仅覆盖 thead th 的旧局部规则。所有走 DialogMarkdown 组件的入口（聊天消息、bot 模板、单条消息分享页、AI 助手）一次性生效；任务描述、报告编辑等直接调用 MarkdownConver 的场景不受影响。

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

resources/assets/js/pages/manage/components/DialogMarkdown.vue

@@ -1,5 +1,5 @@
 <template>
-    <div @click="onCLick" class="markdown-body" v-html="html"></div>
+    <div @click="onCLick" class="markdown-body dialog-markdown" v-html="html"></div>
 </template>
 
 <script>

resources/assets/sass/pages/components/dialog-markdown/markdown.less

@@ -133,6 +133,16 @@ body {
         }
     }
 
+    .dialog-markdown {
+        table {
+            th, td {
+                overflow: hidden;
+                text-overflow: ellipsis;
+                white-space: nowrap;
+            }
+        }
+    }
+
     @keyframes blink-animate {
         0%,to {
             background-color: currentColor

resources/assets/sass/pages/components/dialog-wrapper.scss

@@ -1649,18 +1649,6 @@
                                 background-color: $primary-color;
                             }
                         }
-
-                        .markdown-body {
-                            table {
-                                thead {
-                                    th {
-                                        overflow: hidden;
-                                        text-overflow: ellipsis;
-                                        white-space: nowrap;
-                                    }
-                                }
-                            }
-                        }
                     }
 
                     .dialog-emoji {