🐛 fix(table-designer): 优化表设计触发器修改入口

- 修改触发器从固定弹窗改为对象编辑 SQL 标签页
- 生成删除旧触发器和创建新触发器脚本，便于执行前审查
- 抽出触发器编辑 SQL 构造工具，统一 TriggerViewer 与 TableDesigner 逻辑
- 保留新增触发器原弹窗路径，降低行为变更范围
- 新增触发器编辑入口与 SQL 构造回归测试
Refs #557

frontend/src/components/TableDesigner.trigger-edit.test.ts

@@ -0,0 +1,39 @@
+import { readFileSync } from 'node:fs';
+import path from 'node:path';
+
+import { describe, expect, it } from 'vitest';
+
+const tableDesignerSource = readFileSync(
+  path.resolve(__dirname, './TableDesigner.tsx'),
+  'utf8',
+);
+
+const getFunctionBlock = (source: string, name: string): string => {
+  const start = source.indexOf(`const ${name} = () => {`);
+  expect(start).toBeGreaterThanOrEqual(0);
+  const nextFunction = source.indexOf('\n  const ', start + 1);
+  expect(nextFunction).toBeGreaterThan(start);
+  return source.slice(start, nextFunction);
+};
+
+describe('TableDesigner trigger edit entry', () => {
+  it('opens trigger edits in an object-edit query tab instead of the fixed modal', () => {
+    const editBlock = getFunctionBlock(tableDesignerSource, 'handleEditTrigger');
+
+    expect(editBlock).toContain('setActiveContext({ connectionId: tab.connectionId, dbName });');
+    expect(editBlock).toContain('addTab({');
+    expect(editBlock).toContain("type: 'query'");
+    expect(editBlock).toContain("queryMode: 'object-edit'");
+    expect(editBlock).toContain('buildEditableTriggerSql(selectedTrigger.name, createSql');
+    expect(editBlock).toContain('dropSql: buildDropTriggerSql(selectedTrigger.name)');
+    expect(editBlock).not.toContain('setIsTriggerEditModalOpen(true)');
+  });
+
+  it('keeps trigger creation on the existing modal path', () => {
+    const createBlock = getFunctionBlock(tableDesignerSource, 'handleCreateTrigger');
+
+    expect(createBlock).toContain("setTriggerEditMode('create')");
+    expect(createBlock).toContain('setTriggerEditSql(generateTriggerTemplate())');
+    expect(createBlock).toContain('setIsTriggerEditModalOpen(true)');
+  });
+});