Refactor WebDAV path construction and fix note move operations

- Replace Node.js fetch with Electron net.request for better session handling
- Extract WebDAV path building into reusable private methods with proper URL encoding
- Add helper methods for category path encoding and attachment path construction
- Fix note move operations to use remote category/filename from saved snapshots
- Add ensureCategoryDirectoryExists to handle nested category creation
- Only move/rename attachment folders when note has any

electron/main.cjs

@@ -1,6 +1,6 @@
 const fs = require('node:fs/promises');
 const path = require('node:path');
-const { app, BrowserWindow, dialog, ipcMain } = require('electron');
+const { app, BrowserWindow, dialog, ipcMain, net } = require('electron');
 
 const rendererUrl = process.env.ELECTRON_RENDERER_URL;
 const isDev = Boolean(rendererUrl);
@@ -90,23 +90,55 @@ ipcMain.handle('desktop:http-request', async (_event, payload) => {
   const body =
     payload.bodyBase64 != null
       ? Buffer.from(payload.bodyBase64, 'base64')
-      : payload.bodyText;
+      : payload.bodyText != null
+        ? Buffer.from(payload.bodyText, 'utf8')
+        : null;
 
-  const response = await fetch(payload.url, {
-    method: payload.method || 'GET',
-    headers: payload.headers,
-    body,
+  return await new Promise((resolve, reject) => {
+    const request = net.request({
+      url: payload.url,
+      method: payload.method || 'GET',
+      session: BrowserWindow.getAllWindows()[0]?.webContents.session,
+    });
+
+    for (const [name, value] of Object.entries(payload.headers || {})) {
+      request.setHeader(name, value);
+    }
+
+    request.on('response', (response) => {
+      const chunks = [];
+
+      response.on('data', (chunk) => {
+        chunks.push(Buffer.isBuffer(chunk) ? chunk : Buffer.from(chunk));
+      });
+
+      response.on('end', () => {
+        const headers = {};
+        for (const [name, value] of Object.entries(response.headers)) {
+          headers[name] = Array.isArray(value) ? value.join(', ') : String(value ?? '');
+        }
+
+        const buffer = Buffer.concat(chunks);
+        resolve({
+          ok: response.statusCode >= 200 && response.statusCode < 300,
+          status: response.statusCode,
+          statusText: response.statusMessage || '',
+          headers,
+          bodyBase64: buffer.toString('base64'),
+        });
+      });
+
+      response.on('error', reject);
+    });
+
+    request.on('error', reject);
+
+    if (body && body.length > 0) {
+      request.write(body);
+    }
+
+    request.end();
   });
-
-  const buffer = Buffer.from(await response.arrayBuffer());
-
-  return {
-    ok: response.ok,
-    status: response.status,
-    statusText: response.statusText,
-    headers: Object.fromEntries(response.headers.entries()),
-    bodyBase64: buffer.toString('base64'),
-  };
 });
 
 ipcMain.handle('desktop:export-pdf', async (event, payload) => {