refactor(main): create src/main/{store,index}.js glue layer; new entrypoint at src/main/index.js

package.json

@@ -2,7 +2,7 @@
   "name": "markdown-converter",
   "version": "4.4.2",
   "description": "Professional Markdown editor and universal file converter with PDF editing, batch processing, and syntax highlighting",
-  "main": "src/main.js",
+  "main": "src/main/index.js",
   "scripts": {
     "start": "electron .",
     "test": "jest",

src/main/store.js

@@ -0,0 +1,31 @@
+// src/main/store.js
+// Simple JSON-file preferences store (replaces electron-store)
+
+const { app } = require('electron');
+const path = require('path');
+const fs = require('fs');
+
+const settingsPath = path.join(app.getPath('userData'), 'settings.json');
+
+const store = {
+  get(key, defaultValue) {
+    try {
+      const data = fs.readFileSync(settingsPath, 'utf-8');
+      const settings = JSON.parse(data);
+      return settings[key] !== undefined ? settings[key] : defaultValue;
+    } catch {
+      return defaultValue;
+    }
+  },
+  set(key, value) {
+    let settings = {};
+    try {
+      const data = fs.readFileSync(settingsPath, 'utf-8');
+      settings = JSON.parse(data);
+    } catch {}
+    settings[key] = value;
+    fs.writeFileSync(settingsPath, JSON.stringify(settings, null, 2));
+  }
+};
+
+module.exports = store;