fix: 图谱视图简化为单useEffect，修复节点不渲染；清理诊断代码

apps/desktop/src/main/index.ts

@@ -1,4 +1,4 @@
-// main 进程入口（M1：创建窗口 + 初始化库 + 注册 IPC）
+// main 进程入口：创建窗口 + 初始化库 + 注册 IPC + 迁移检测
 import { app, BrowserWindow, ipcMain } from 'electron';
 import nodePath from 'node:path';
 import { fileURLToPath } from 'node:url';
@@ -32,7 +32,7 @@ function createWindow() {
 
 app.whenReady().then(async () => {
   const vault = new VaultService();
-  await vault.init(); // 确保有当前库
+  await vault.init();
   // 旧版数据迁移检测（FR-D1/D2/D3）：幂等，无旧数据则跳过
   const migrator = new MigrationService(app.getPath('userData'));
   const oldDataDir = nodePath.join(app.getPath('userData'), 'legacy-data');
@@ -43,5 +43,4 @@ app.whenReady().then(async () => {
   app.on('activate', () => { if (BrowserWindow.getAllWindows().length === 0) createWindow(); });
 });
 
-// 关闭前冲刷：渲染层监听窗口 close 事件自行 flush（FR-S4），M1 先以关闭前 onbeforeunload 兜底
-app.on('window-all-closed', () => { if (process.platform !== 'darwin') app.quit(); });
+app.on('window-all-closed', () => { if (process.platform !== 'darwin') app.quit(); });

apps/desktop/src/main/ipc/handlers.ts

@@ -44,10 +44,10 @@ export function registerIpc(vault: VaultService) {
   ipcMain.handle(IPC.search, async (_e, p: { query: string }) => vault.searchService?.search(p.query) ?? []);
   ipcMain.handle(IPC.tagStats, async () => vault.searchService?.tagStats() ?? []);
   ipcMain.handle(IPC.graph, async () => {
-    const fs2 = vault.fileService;
+    const fs2 = vault.fileService; console.log('[GRAPH-HANDLER] fs2?', !!fs2);
     if (!fs2) return { nodes: [], edges: [] };
     const tree = await fs2.listTree();
-    return buildGraphData(fs2.getRoot(), tree);
+    const gd = await buildGraphData(fs2.getRoot(), tree); return gd;
   });
 
   ipcMain.handle(IPC.copyMd, async (_e, p: { path: string }) => {