diff --git a/electron/eslint.config.mjs b/electron/eslint.config.mjs
index 8bd95ed7..77b52cb4 100644
--- a/electron/eslint.config.mjs
+++ b/electron/eslint.config.mjs
@@ -41,4 +41,26 @@ export default [
       'no-plusplus': 'off',
     },
   },
+  // CommonJS files (preload scripts must be CJS when sandbox is enabled)
+  {
+    files: ['**/*.cjs'],
+    plugins: {
+      prettier: prettierPlugin,
+    },
+    languageOptions: {
+      ecmaVersion: 2022,
+      sourceType: 'commonjs',
+      globals: {
+        ...globals.node,
+        ...globals.es2021,
+      },
+    },
+    rules: {
+      'prettier/prettier': 'error',
+      ...prettierConfig.rules,
+      'max-len': 'off',
+      'no-unused-vars': 'warn',
+      'no-plusplus': 'off',
+    },
+  },
 ];
diff --git a/electron/main.js b/electron/main.js
index aca9655d..16531159 100644
--- a/electron/main.js
+++ b/electron/main.js
@@ -4,14 +4,19 @@
  * Handles window creation, IPC communication, and app lifecycle.
  */
 
-const { app, BrowserWindow, ipcMain } = require('electron');
-const path = require('path');
-const url = require('url');
+import { app, BrowserWindow, ipcMain } from 'electron';
+import path from 'path';
+import url from 'url';
+import { fileURLToPath } from 'url';
+
+// ESM equivalent of __dirname
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
 
 // Services
-const ConnectionManager = require('./services/ConnectionManager');
-const VersionChecker = require('./services/VersionChecker');
-const MDNSDiscovery = require('./services/MDNSDiscovery');
+import ConnectionManager from './services/ConnectionManager.js';
+import VersionChecker from './services/VersionChecker.js';
+import MDNSDiscovery from './services/MDNSDiscovery.js';
 
 // Determine if running in development mode
 const isDev = process.argv.includes('--dev') || process.env.NODE_ENV === 'development';
@@ -32,7 +37,7 @@ function createWindow() {
     minWidth: 800,
     minHeight: 600,
     webPreferences: {
-      preload: path.join(__dirname, 'preload.js'),
+      preload: path.join(__dirname, 'preload.cjs'),
       nodeIntegration: false,
       contextIsolation: true,
       sandbox: true,
diff --git a/electron/package-lock.json b/electron/package-lock.json
index de3a0092..75aa1920 100644
--- a/electron/package-lock.json
+++ b/electron/package-lock.json
@@ -10,8 +10,7 @@
       "license": "GPL-3.0",
       "dependencies": {
         "bonjour-service": "^1.3.0",
-        "electron-store": "^8.2.0",
-        "node-fetch": "^3.3.2"
+        "electron-store": "^11.0.2"
       },
       "devDependencies": {
         "@electron-forge/cli": "^7.11.1",
@@ -20,11 +19,11 @@
         "@electron-forge/maker-squirrel": "^7.11.1",
         "@electron-forge/maker-zip": "^7.11.1",
         "@eslint/js": "^9.39.2",
-        "electron": "^32.2.10",
+        "electron": "^40.0.0",
         "eslint": "^9.39.2",
         "eslint-config-prettier": "^10.1.8",
         "eslint-plugin-prettier": "^5.5.5",
-        "globals": "^15.14.0",
+        "globals": "^17.1.0",
         "prettier": "^3.8.1"
       },
       "engines": {
@@ -1894,6 +1893,7 @@
       "version": "2.1.1",
       "resolved": "https://registry.npmjs.org/ajv-formats/-/ajv-formats-2.1.1.tgz",
       "integrity": "sha512-Wx0Kx52hxE7C18hkMEggYlEifqWZtYaRgouJor+WMdPnQyEK13vgEWyVNup7SoeeoLMsr4kf5h6dOW11I15MUA==",
+      "dev": true,
       "license": "MIT",
       "dependencies": {
         "ajv": "^8.0.0"
@@ -1980,12 +1980,13 @@
       }
     },
     "node_modules/atomically": {
-      "version": "1.7.0",
-      "resolved": "https://registry.npmjs.org/atomically/-/atomically-1.7.0.tgz",
-      "integrity": "sha512-Xcz9l0z7y9yQ9rdDaxlmaI4uJHf/T8g9hOEzJcsEqX2SjCj4J20uK7+ldkDHMbpJDK76wF7xEIgxc/vSlsfw5w==",
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/atomically/-/atomically-2.1.0.tgz",
+      "integrity": "sha512-+gDffFXRW6sl/HCwbta7zK4uNqbPjv4YJEAdz7Vu+FLQHe77eZ4bvbJGi4hE0QPeJlMYMA3piXEr1UL3dAwx7Q==",
       "license": "MIT",
-      "engines": {
-        "node": ">=10.12.0"
+      "dependencies": {
+        "stubborn-fs": "^2.0.0",
+        "when-exit": "^2.1.4"
       }
     },
     "node_modules/author-regex": {
@@ -2562,24 +2563,52 @@
       "license": "MIT"
     },
     "node_modules/conf": {
-      "version": "10.2.0",
-      "resolved": "https://registry.npmjs.org/conf/-/conf-10.2.0.tgz",
-      "integrity": "sha512-8fLl9F04EJqjSqH+QjITQfJF8BrOVaYr1jewVgSRAEWePfxT0sku4w2hrGQ60BC/TNLGQ2pgxNlTbWQmMPFvXg==",
+      "version": "15.0.2",
+      "resolved": "https://registry.npmjs.org/conf/-/conf-15.0.2.tgz",
+      "integrity": "sha512-JBSrutapCafTrddF9dH3lc7+T2tBycGF4uPkI4Js+g4vLLEhG6RZcFi3aJd5zntdf5tQxAejJt8dihkoQ/eSJw==",
       "license": "MIT",
       "dependencies": {
-        "ajv": "^8.6.3",
-        "ajv-formats": "^2.1.1",
-        "atomically": "^1.7.0",
-        "debounce-fn": "^4.0.0",
-        "dot-prop": "^6.0.1",
-        "env-paths": "^2.2.1",
-        "json-schema-typed": "^7.0.3",
-        "onetime": "^5.1.2",
-        "pkg-up": "^3.1.0",
-        "semver": "^7.3.5"
+        "ajv": "^8.17.1",
+        "ajv-formats": "^3.0.1",
+        "atomically": "^2.0.3",
+        "debounce-fn": "^6.0.0",
+        "dot-prop": "^10.0.0",
+        "env-paths": "^3.0.0",
+        "json-schema-typed": "^8.0.1",
+        "semver": "^7.7.2",
+        "uint8array-extras": "^1.5.0"
       },
       "engines": {
-        "node": ">=12"
+        "node": ">=20"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
+    "node_modules/conf/node_modules/ajv-formats": {
+      "version": "3.0.1",
+      "resolved": "https://registry.npmjs.org/ajv-formats/-/ajv-formats-3.0.1.tgz",
+      "integrity": "sha512-8iUql50EUR+uUcdRQ3HDqa6EVyo3docL8g5WJ3FNcWmu62IbkGUue/pEyLBW8VGKKucTPgqeks4fIU1DA4yowQ==",
+      "license": "MIT",
+      "dependencies": {
+        "ajv": "^8.0.0"
+      },
+      "peerDependencies": {
+        "ajv": "^8.0.0"
+      },
+      "peerDependenciesMeta": {
+        "ajv": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/conf/node_modules/env-paths": {
+      "version": "3.0.0",
+      "resolved": "https://registry.npmjs.org/env-paths/-/env-paths-3.0.0.tgz",
+      "integrity": "sha512-dtJUTepzMW3Lm/NPxRf3wP4642UWhjL2sQxc+ym2YMj1m/H2zDNQOlezafzkHwn6sMstjHTwG6iQQsctDW/b1A==",
+      "license": "MIT",
+      "engines": {
+        "node": "^12.20.0 || ^14.13.1 || >=16.0.0"
       },
       "funding": {
         "url": "https://github.com/sponsors/sindresorhus"
@@ -2631,25 +2660,16 @@
         "node": ">=12.10"
       }
     },
-    "node_modules/data-uri-to-buffer": {
-      "version": "4.0.1",
-      "resolved": "https://registry.npmjs.org/data-uri-to-buffer/-/data-uri-to-buffer-4.0.1.tgz",
-      "integrity": "sha512-0R9ikRb668HB7QDxT1vkpuUBtqc53YyAwMwGeUFKRojY/NWKvdZ+9UYtRfGmhqNbRkTSVpMbmyhXipFFv2cb/A==",
-      "license": "MIT",
-      "engines": {
-        "node": ">= 12"
-      }
-    },
     "node_modules/debounce-fn": {
-      "version": "4.0.0",
-      "resolved": "https://registry.npmjs.org/debounce-fn/-/debounce-fn-4.0.0.tgz",
-      "integrity": "sha512-8pYCQiL9Xdcg0UPSD3d+0KMlOjp+KGU5EPwYddgzQ7DATsg4fuUDjQtsYLmWjnk2obnNHgV3vE2Y4jejSOJVBQ==",
+      "version": "6.0.0",
+      "resolved": "https://registry.npmjs.org/debounce-fn/-/debounce-fn-6.0.0.tgz",
+      "integrity": "sha512-rBMW+F2TXryBwB54Q0d8drNEI+TfoS9JpNTAoVpukbWEhjXQq4rySFYLaqXMFXwdv61Zb2OHtj5bviSoimqxRQ==",
       "license": "MIT",
       "dependencies": {
-        "mimic-fn": "^3.0.0"
+        "mimic-function": "^5.0.0"
       },
       "engines": {
-        "node": ">=10"
+        "node": ">=18"
       },
       "funding": {
         "url": "https://github.com/sponsors/sindresorhus"
@@ -2812,15 +2832,30 @@
       }
     },
     "node_modules/dot-prop": {
-      "version": "6.0.1",
-      "resolved": "https://registry.npmjs.org/dot-prop/-/dot-prop-6.0.1.tgz",
-      "integrity": "sha512-tE7ztYzXHIeyvc7N+hR3oi7FIbf/NIjVP9hmAt3yMXzrQ072/fpjGLx2GxNxGxUl5V73MEqYzioOMoVhGMJ5cA==",
+      "version": "10.1.0",
+      "resolved": "https://registry.npmjs.org/dot-prop/-/dot-prop-10.1.0.tgz",
+      "integrity": "sha512-MVUtAugQMOff5RnBy2d9N31iG0lNwg1qAoAOn7pOK5wf94WIaE3My2p3uwTQuvS2AcqchkcR3bHByjaM0mmi7Q==",
       "license": "MIT",
       "dependencies": {
-        "is-obj": "^2.0.0"
+        "type-fest": "^5.0.0"
       },
       "engines": {
-        "node": ">=10"
+        "node": ">=20"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
+    "node_modules/dot-prop/node_modules/type-fest": {
+      "version": "5.4.1",
+      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-5.4.1.tgz",
+      "integrity": "sha512-xygQcmneDyzsEuKZrFbRMne5HDqMs++aFzefrJTgEIKjQ3rekM+RPfFCVq2Gp1VIDqddoYeppCj4Pcb+RZW0GQ==",
+      "license": "(MIT OR CC0-1.0)",
+      "dependencies": {
+        "tagged-tag": "^1.0.0"
+      },
+      "engines": {
+        "node": ">=20"
       },
       "funding": {
         "url": "https://github.com/sponsors/sindresorhus"
@@ -2834,15 +2869,15 @@
       "license": "MIT"
     },
     "node_modules/electron": {
-      "version": "32.3.3",
-      "resolved": "https://registry.npmjs.org/electron/-/electron-32.3.3.tgz",
-      "integrity": "sha512-7FT8tDg+MueAw8dBn5LJqDvlM4cZkKJhXfgB3w7P5gvSoUQVAY6LIQcXJxgL+vw2rIRY/b9ak7ZBFbCMF2Bk4w==",
+      "version": "40.0.0",
+      "resolved": "https://registry.npmjs.org/electron/-/electron-40.0.0.tgz",
+      "integrity": "sha512-UyBy5yJ0/wm4gNugCtNPjvddjAknMTuXR2aCHioXicH7aKRKGDBPp4xqTEi/doVcB3R+MN3wfU9o8d/9pwgK2A==",
       "dev": true,
       "hasInstallScript": true,
       "license": "MIT",
       "dependencies": {
         "@electron/get": "^2.0.0",
-        "@types/node": "^20.9.0",
+        "@types/node": "^24.9.0",
         "extract-zip": "^2.0.1"
       },
       "bin": {
@@ -3255,25 +3290,31 @@
       }
     },
     "node_modules/electron-store": {
-      "version": "8.2.0",
-      "resolved": "https://registry.npmjs.org/electron-store/-/electron-store-8.2.0.tgz",
-      "integrity": "sha512-ukLL5Bevdil6oieAOXz3CMy+OgaItMiVBg701MNlG6W5RaC0AHN7rvlqTCmeb6O7jP0Qa1KKYTE0xV0xbhF4Hw==",
+      "version": "11.0.2",
+      "resolved": "https://registry.npmjs.org/electron-store/-/electron-store-11.0.2.tgz",
+      "integrity": "sha512-4VkNRdN+BImL2KcCi41WvAYbh6zLX5AUTi4so68yPqiItjbgTjqpEnGAqasgnG+lB6GuAyUltKwVopp6Uv+gwQ==",
       "license": "MIT",
       "dependencies": {
-        "conf": "^10.2.0",
-        "type-fest": "^2.17.0"
+        "conf": "^15.0.2",
+        "type-fest": "^5.0.1"
+      },
+      "engines": {
+        "node": ">=20"
       },
       "funding": {
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
     "node_modules/electron-store/node_modules/type-fest": {
-      "version": "2.19.0",
-      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-2.19.0.tgz",
-      "integrity": "sha512-RAH822pAdBgcNMAfWnCBU3CFZcfZ/i1eZjwFU/dsLKumyuuP3niueg2UAukXYF0E2AAoc82ZSSf9J0WQBinzHA==",
+      "version": "5.4.1",
+      "resolved": "https://registry.npmjs.org/type-fest/-/type-fest-5.4.1.tgz",
+      "integrity": "sha512-xygQcmneDyzsEuKZrFbRMne5HDqMs++aFzefrJTgEIKjQ3rekM+RPfFCVq2Gp1VIDqddoYeppCj4Pcb+RZW0GQ==",
       "license": "(MIT OR CC0-1.0)",
+      "dependencies": {
+        "tagged-tag": "^1.0.0"
+      },
       "engines": {
-        "node": ">=12.20"
+        "node": ">=20"
       },
       "funding": {
         "url": "https://github.com/sponsors/sindresorhus"
@@ -3369,13 +3410,13 @@
       }
     },
     "node_modules/electron/node_modules/@types/node": {
-      "version": "20.19.30",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-20.19.30.tgz",
-      "integrity": "sha512-WJtwWJu7UdlvzEAUm484QNg5eAoq5QR08KDNx7g45Usrs2NtOPiX8ugDqmKdXkyL03rBqU5dYNYVQetEpBHq2g==",
+      "version": "24.10.9",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-24.10.9.tgz",
+      "integrity": "sha512-ne4A0IpG3+2ETuREInjPNhUGis1SFjv1d5asp8MzEAGtOZeTeHVDOYqOgqfhvseqg/iXty2hjBf1zAOb7RNiNw==",
       "dev": true,
       "license": "MIT",
       "dependencies": {
-        "undici-types": "~6.21.0"
+        "undici-types": "~7.16.0"
       }
     },
     "node_modules/electron/node_modules/fs-extra": {
@@ -3413,6 +3454,13 @@
         "semver": "bin/semver.js"
       }
     },
+    "node_modules/electron/node_modules/undici-types": {
+      "version": "7.16.0",
+      "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-7.16.0.tgz",
+      "integrity": "sha512-Zz+aZWSj8LE6zoxD+xrjh4VfkIG8Ya6LvYkZqtUQGJPZjYl53ypCaUwWqo7eI0x66KBGeRo+mlBEkMSeSZ38Nw==",
+      "dev": true,
+      "license": "MIT"
+    },
     "node_modules/electron/node_modules/universalify": {
       "version": "0.1.2",
       "resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.2.tgz",
@@ -3458,6 +3506,7 @@
       "version": "2.2.1",
       "resolved": "https://registry.npmjs.org/env-paths/-/env-paths-2.2.1.tgz",
       "integrity": "sha512-+h1lkLKhZMTYjog1VEpJNG7NZJWcuc2DDk/qsqSTRRCOXiLjeQ1d1/udrUGhqMxUgAlwKNZ0cf2uqan5GLuS2A==",
+      "dev": true,
       "license": "MIT",
       "engines": {
         "node": ">=6"
@@ -4076,29 +4125,6 @@
         "pend": "~1.2.0"
       }
     },
-    "node_modules/fetch-blob": {
-      "version": "3.2.0",
-      "resolved": "https://registry.npmjs.org/fetch-blob/-/fetch-blob-3.2.0.tgz",
-      "integrity": "sha512-7yAQpD2UMJzLi1Dqv7qFYnPbaPx7ZfFK6PiIxQ4PfkGPyNyl2Ugx+a/umUonmKqjhM4DnfbMvdX6otXq83soQQ==",
-      "funding": [
-        {
-          "type": "github",
-          "url": "https://github.com/sponsors/jimmywarting"
-        },
-        {
-          "type": "paypal",
-          "url": "https://paypal.me/jimmywarting"
-        }
-      ],
-      "license": "MIT",
-      "dependencies": {
-        "node-domexception": "^1.0.0",
-        "web-streams-polyfill": "^3.0.3"
-      },
-      "engines": {
-        "node": "^12.20 || >= 14.13"
-      }
-    },
     "node_modules/file-entry-cache": {
       "version": "8.0.0",
       "resolved": "https://registry.npmjs.org/file-entry-cache/-/file-entry-cache-8.0.0.tgz",
@@ -4205,18 +4231,6 @@
         "node": ">= 12"
       }
     },
-    "node_modules/formdata-polyfill": {
-      "version": "4.0.10",
-      "resolved": "https://registry.npmjs.org/formdata-polyfill/-/formdata-polyfill-4.0.10.tgz",
-      "integrity": "sha512-buewHzMvYL29jdeQTVILecSaZKnt/RJWjoZCF5OW60Z67/GmSLBkOFM7qh1PI3zFNtJbaZL5eQu1vLfazOwj4g==",
-      "license": "MIT",
-      "dependencies": {
-        "fetch-blob": "^3.1.2"
-      },
-      "engines": {
-        "node": ">=12.20.0"
-      }
-    },
     "node_modules/fs-extra": {
       "version": "10.1.0",
       "resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-10.1.0.tgz",
@@ -4438,9 +4452,9 @@
       }
     },
     "node_modules/globals": {
-      "version": "15.15.0",
-      "resolved": "https://registry.npmjs.org/globals/-/globals-15.15.0.tgz",
-      "integrity": "sha512-7ACyT3wmyp3I61S4fG682L0VA2RGD9otkqGJIwNUMF1SWUombIIk+af1unuDYgMm082aHYwD+mzJvv9Iu8dsgg==",
+      "version": "17.1.0",
+      "resolved": "https://registry.npmjs.org/globals/-/globals-17.1.0.tgz",
+      "integrity": "sha512-8HoIcWI5fCvG5NADj4bDav+er9B9JMj2vyL2pI8D0eismKyUvPLTSs+Ln3wqhwcp306i73iyVnEKx3F6T47TGw==",
       "dev": true,
       "license": "MIT",
       "engines": {
@@ -4842,15 +4856,6 @@
         "node": ">=0.12.0"
       }
     },
-    "node_modules/is-obj": {
-      "version": "2.0.0",
-      "resolved": "https://registry.npmjs.org/is-obj/-/is-obj-2.0.0.tgz",
-      "integrity": "sha512-drqDG3cbczxxEJRoOXcOjtdp1J/lyp1mNn0xaznRs8+muBhgQcrnbspox5X5fOw0HnMnbfDzvnEMEtqDEJEo8w==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=8"
-      }
-    },
     "node_modules/is-stream": {
       "version": "1.1.0",
       "resolved": "https://registry.npmjs.org/is-stream/-/is-stream-1.1.0.tgz",
@@ -4969,9 +4974,9 @@
       "license": "MIT"
     },
     "node_modules/json-schema-typed": {
-      "version": "7.0.3",
-      "resolved": "https://registry.npmjs.org/json-schema-typed/-/json-schema-typed-7.0.3.tgz",
-      "integrity": "sha512-7DE8mpG+/fVw+dTpjbxnx47TaMnDfOI1jwft9g1VybltZCduyRQPJPvc+zzKY9WPHxhPWczyFuYa6I8Mw4iU5A==",
+      "version": "8.0.2",
+      "resolved": "https://registry.npmjs.org/json-schema-typed/-/json-schema-typed-8.0.2.tgz",
+      "integrity": "sha512-fQhoXdcvc3V28x7C7BMs4P5+kNlgUURe2jmUT1T//oBRMDrqy1QPelJimwZGo7Hg9VPV3EQV5Bnq4hbFy2vetA==",
       "license": "BSD-2-Clause"
     },
     "node_modules/json-stable-stringify-without-jsonify": {
@@ -5462,13 +5467,16 @@
         "node": ">= 0.6"
       }
     },
-    "node_modules/mimic-fn": {
-      "version": "3.1.0",
-      "resolved": "https://registry.npmjs.org/mimic-fn/-/mimic-fn-3.1.0.tgz",
-      "integrity": "sha512-Ysbi9uYW9hFyfrThdDEQuykN4Ey6BuwPD2kpI5ES/nFTDn/98yxYNLZJcgUAKPT/mcrLLKaGzJR9YVxJrIdASQ==",
+    "node_modules/mimic-function": {
+      "version": "5.0.1",
+      "resolved": "https://registry.npmjs.org/mimic-function/-/mimic-function-5.0.1.tgz",
+      "integrity": "sha512-VP79XUPxV2CigYP3jWwAUFSku2aKqBH7uTAapFWCBqutsbmDo96KY5o8uh6U+/YSIn5OxJnXp73beVkpqMIGhA==",
       "license": "MIT",
       "engines": {
-        "node": ">=8"
+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
       }
     },
     "node_modules/mimic-response": {
@@ -5698,44 +5706,6 @@
         "semver": "^7.3.5"
       }
     },
-    "node_modules/node-domexception": {
-      "version": "1.0.0",
-      "resolved": "https://registry.npmjs.org/node-domexception/-/node-domexception-1.0.0.tgz",
-      "integrity": "sha512-/jKZoMpw0F8GRwl4/eLROPA3cfcXtLApP0QzLmUT/HuPCZWyB7IY9ZrMeKw2O/nFIqPQB3PVM9aYm0F312AXDQ==",
-      "deprecated": "Use your platform's native DOMException instead",
-      "funding": [
-        {
-          "type": "github",
-          "url": "https://github.com/sponsors/jimmywarting"
-        },
-        {
-          "type": "github",
-          "url": "https://paypal.me/jimmywarting"
-        }
-      ],
-      "license": "MIT",
-      "engines": {
-        "node": ">=10.5.0"
-      }
-    },
-    "node_modules/node-fetch": {
-      "version": "3.3.2",
-      "resolved": "https://registry.npmjs.org/node-fetch/-/node-fetch-3.3.2.tgz",
-      "integrity": "sha512-dRB78srN/l6gqWulah9SrxeYnxeddIG30+GOqK/9OlLVyLg3HPnr6SqOWTWOXKRwC2eGYCkZ59NNuSgvSrpgOA==",
-      "license": "MIT",
-      "dependencies": {
-        "data-uri-to-buffer": "^4.0.0",
-        "fetch-blob": "^3.1.4",
-        "formdata-polyfill": "^4.0.10"
-      },
-      "engines": {
-        "node": "^12.20.0 || ^14.13.1 || >=16.0.0"
-      },
-      "funding": {
-        "type": "opencollective",
-        "url": "https://opencollective.com/node-fetch"
-      }
-    },
     "node_modules/node-releases": {
       "version": "2.0.27",
       "resolved": "https://registry.npmjs.org/node-releases/-/node-releases-2.0.27.tgz",
@@ -5843,6 +5813,7 @@
       "version": "5.1.2",
       "resolved": "https://registry.npmjs.org/onetime/-/onetime-5.1.2.tgz",
       "integrity": "sha512-kbpaSSGJTWdAY5KPVeMOKXSrPtr8C8C7wodJbcsd51jRnmD+GZu8Y0VoU6Dm5Z4vWr0Ig/1NKuWRKf7j5aaYSg==",
+      "dev": true,
       "license": "MIT",
       "dependencies": {
         "mimic-fn": "^2.1.0"
@@ -5858,6 +5829,7 @@
       "version": "2.1.0",
       "resolved": "https://registry.npmjs.org/mimic-fn/-/mimic-fn-2.1.0.tgz",
       "integrity": "sha512-OqbOk5oEQeAZ8WXWydlu9HJjz9WVdEIvamMCcXmuqUYjTknH/sqsWvhQ3vgwKFRR1HpjvNBKQ37nbJgYzGqGcg==",
+      "dev": true,
       "license": "MIT",
       "engines": {
         "node": ">=6"
@@ -6037,15 +6009,6 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
-    "node_modules/p-try": {
-      "version": "2.2.0",
-      "resolved": "https://registry.npmjs.org/p-try/-/p-try-2.2.0.tgz",
-      "integrity": "sha512-R4nPAVTAU0B9D35/Gk3uJf/7XYbQcyohSKdvAxIRSNghFl4e71hVoGnBNQz9cWaXxO2I10KTC+3jMdvvoKw6dQ==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=6"
-      }
-    },
     "node_modules/parent-module": {
       "version": "1.0.1",
       "resolved": "https://registry.npmjs.org/parent-module/-/parent-module-1.0.1.tgz",
@@ -6187,79 +6150,6 @@
         "node": ">=0.10.0"
       }
     },
-    "node_modules/pkg-up": {
-      "version": "3.1.0",
-      "resolved": "https://registry.npmjs.org/pkg-up/-/pkg-up-3.1.0.tgz",
-      "integrity": "sha512-nDywThFk1i4BQK4twPQ6TA4RT8bDY96yeuCVBWL3ePARCiEKDRSrNGbFIgUJpLp+XeIR65v8ra7WuJOFUBtkMA==",
-      "license": "MIT",
-      "dependencies": {
-        "find-up": "^3.0.0"
-      },
-      "engines": {
-        "node": ">=8"
-      }
-    },
-    "node_modules/pkg-up/node_modules/find-up": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/find-up/-/find-up-3.0.0.tgz",
-      "integrity": "sha512-1yD6RmLI1XBfxugvORwlck6f75tYL+iR0jqwsOrOxMZyGYqUuDhJ0l4AXdO1iX/FTs9cBAMEk1gWSEx1kSbylg==",
-      "license": "MIT",
-      "dependencies": {
-        "locate-path": "^3.0.0"
-      },
-      "engines": {
-        "node": ">=6"
-      }
-    },
-    "node_modules/pkg-up/node_modules/locate-path": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/locate-path/-/locate-path-3.0.0.tgz",
-      "integrity": "sha512-7AO748wWnIhNqAuaty2ZWHkQHRSNfPVIsPIfwEOWO22AmaoVrWavlOcMR5nzTLNYvp36X220/maaRsrec1G65A==",
-      "license": "MIT",
-      "dependencies": {
-        "p-locate": "^3.0.0",
-        "path-exists": "^3.0.0"
-      },
-      "engines": {
-        "node": ">=6"
-      }
-    },
-    "node_modules/pkg-up/node_modules/p-limit": {
-      "version": "2.3.0",
-      "resolved": "https://registry.npmjs.org/p-limit/-/p-limit-2.3.0.tgz",
-      "integrity": "sha512-//88mFWSJx8lxCzwdAABTJL2MyWB12+eIY7MDL2SqLmAkeKU9qxRvWuSyTjm3FUmpBEMuFfckAIqEaVGUDxb6w==",
-      "license": "MIT",
-      "dependencies": {
-        "p-try": "^2.0.0"
-      },
-      "engines": {
-        "node": ">=6"
-      },
-      "funding": {
-        "url": "https://github.com/sponsors/sindresorhus"
-      }
-    },
-    "node_modules/pkg-up/node_modules/p-locate": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/p-locate/-/p-locate-3.0.0.tgz",
-      "integrity": "sha512-x+12w/To+4GFfgJhBEpiDcLozRJGegY+Ei7/z0tSLkMmxGZNybVMSfWj9aJn8Z5Fc7dBUNJOOVgPv2H7IwulSQ==",
-      "license": "MIT",
-      "dependencies": {
-        "p-limit": "^2.0.0"
-      },
-      "engines": {
-        "node": ">=6"
-      }
-    },
-    "node_modules/pkg-up/node_modules/path-exists": {
-      "version": "3.0.0",
-      "resolved": "https://registry.npmjs.org/path-exists/-/path-exists-3.0.0.tgz",
-      "integrity": "sha512-bpC7GYwiDYQ4wYLe+FA8lhRjhQCMcQGuSgGGqDkg/QerRWw9CmGRT0iSOVRSZJ29NMLZgIzqaljJ63oaL4NIJQ==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=4"
-      }
-    },
     "node_modules/plist": {
       "version": "3.1.0",
       "resolved": "https://registry.npmjs.org/plist/-/plist-3.1.0.tgz",
@@ -7210,6 +7100,21 @@
         "node": ">=0.8.0"
       }
     },
+    "node_modules/stubborn-fs": {
+      "version": "2.0.0",
+      "resolved": "https://registry.npmjs.org/stubborn-fs/-/stubborn-fs-2.0.0.tgz",
+      "integrity": "sha512-Y0AvSwDw8y+nlSNFXMm2g6L51rBGdAQT20J3YSOqxC53Lo3bjWRtr2BKcfYoAf352WYpsZSTURrA0tqhfgudPA==",
+      "license": "MIT",
+      "dependencies": {
+        "stubborn-utils": "^1.0.1"
+      }
+    },
+    "node_modules/stubborn-utils": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/stubborn-utils/-/stubborn-utils-1.0.2.tgz",
+      "integrity": "sha512-zOh9jPYI+xrNOyisSelgym4tolKTJCQd5GBhK0+0xJvcYDcwlOoxF/rnFKQ2KRZknXSG9jWAp66fwP6AxN9STg==",
+      "license": "MIT"
+    },
     "node_modules/sumchecker": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/sumchecker/-/sumchecker-3.0.1.tgz",
@@ -7265,6 +7170,18 @@
         "url": "https://opencollective.com/synckit"
       }
     },
+    "node_modules/tagged-tag": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/tagged-tag/-/tagged-tag-1.0.0.tgz",
+      "integrity": "sha512-yEFYrVhod+hdNyx7g5Bnkkb0G6si8HJurOoOEgC8B/O0uXLHlaey/65KRv6cuWBNhBgHKAROVpc7QyYqE5gFng==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=20"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/tapable": {
       "version": "2.3.0",
       "resolved": "https://registry.npmjs.org/tapable/-/tapable-2.3.0.tgz",
@@ -7544,6 +7461,18 @@
         "node": ">=14.17"
       }
     },
+    "node_modules/uint8array-extras": {
+      "version": "1.5.0",
+      "resolved": "https://registry.npmjs.org/uint8array-extras/-/uint8array-extras-1.5.0.tgz",
+      "integrity": "sha512-rvKSBiC5zqCCiDZ9kAOszZcDvdAHwwIKJG33Ykj43OKcWsnmcBRL09YTU4nOeHZ8Y2a7l1MgTd08SBe9A8Qj6A==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=18"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/sindresorhus"
+      }
+    },
     "node_modules/undici-types": {
       "version": "6.21.0",
       "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-6.21.0.tgz",
@@ -7684,15 +7613,6 @@
         "defaults": "^1.0.3"
       }
     },
-    "node_modules/web-streams-polyfill": {
-      "version": "3.3.3",
-      "resolved": "https://registry.npmjs.org/web-streams-polyfill/-/web-streams-polyfill-3.3.3.tgz",
-      "integrity": "sha512-d2JWLCivmZYTSIoge9MsgFCZrt571BikcWGYkjC1khllbTeDlGqZ2D8vD8E/lJa8WGWbb7Plm8/XJYV7IJHZZw==",
-      "license": "MIT",
-      "engines": {
-        "node": ">= 8"
-      }
-    },
     "node_modules/webidl-conversions": {
       "version": "3.0.1",
       "resolved": "https://registry.npmjs.org/webidl-conversions/-/webidl-conversions-3.0.1.tgz",
@@ -7771,6 +7691,12 @@
         "webidl-conversions": "^3.0.0"
       }
     },
+    "node_modules/when-exit": {
+      "version": "2.1.5",
+      "resolved": "https://registry.npmjs.org/when-exit/-/when-exit-2.1.5.tgz",
+      "integrity": "sha512-VGkKJ564kzt6Ms1dbgPP/yuIoQCrsFAnRbptpC5wOEsDaNsbCB2bnfnaA8i/vRs5tjUSEOtIuvl9/MyVsvQZCg==",
+      "license": "MIT"
+    },
     "node_modules/which": {
       "version": "2.0.2",
       "resolved": "https://registry.npmjs.org/which/-/which-2.0.2.tgz",
diff --git a/electron/package.json b/electron/package.json
index 09374bed..ccdf8901 100644
--- a/electron/package.json
+++ b/electron/package.json
@@ -5,6 +5,7 @@
   "author": "DreamTeamProd",
   "license": "GPL-3.0",
   "main": "main.js",
+  "type": "module",
   "private": true,
   "scripts": {
     "start": "electron .",
@@ -13,23 +14,22 @@
     "make": "electron-forge make",
     "build": "cd ../client && BUILD_TARGET=electron npm run build && cd ../electron && npm run make",
     "lint": "npm run format && npm run lint:eslint",
-    "lint:eslint": "eslint '**/*.js' --fix",
+    "lint:eslint": "eslint '**/*.{js,cjs}' --fix",
     "ci-lint": "npm run format:check && npm run lint:eslint-check",
-    "lint:eslint-check": "eslint '**/*.js'",
-    "format": "prettier --write '**/*.{js,json}'",
-    "format:check": "prettier --check '**/*.{js,json}'"
+    "lint:eslint-check": "eslint '**/*.{js,cjs}'",
+    "format": "prettier --write '**/*.{js,cjs,json}'",
+    "format:check": "prettier --check '**/*.{js,cjs,json}'"
   },
   "engines": {
     "npm": ">=11.0.0 <12",
     "node": ">=24.0.0 <25"
   },
   "dependencies": {
-    "electron-store": "^8.2.0",
-    "bonjour-service": "^1.3.0",
-    "node-fetch": "^3.3.2"
+    "electron-store": "^11.0.2",
+    "bonjour-service": "^1.3.0"
   },
   "devDependencies": {
-    "electron": "^32.2.10",
+    "electron": "^40.0.0",
     "@electron-forge/cli": "^7.11.1",
     "@electron-forge/maker-squirrel": "^7.11.1",
     "@electron-forge/maker-zip": "^7.11.1",
@@ -39,7 +39,7 @@
     "eslint": "^9.39.2",
     "eslint-config-prettier": "^10.1.8",
     "eslint-plugin-prettier": "^5.5.5",
-    "globals": "^15.14.0",
+    "globals": "^17.1.0",
     "prettier": "^3.8.1"
   },
   "config": {
diff --git a/electron/preload.js b/electron/preload.cjs
similarity index 91%
rename from electron/preload.js
rename to electron/preload.cjs
index f47953e6..d1539f2f 100644
--- a/electron/preload.js
+++ b/electron/preload.cjs
@@ -3,6 +3,9 @@
  *
  * Safely exposes IPC methods to the renderer process via contextBridge.
  * This creates the window.electronAPI interface used by the platform layer.
+ *
+ * Note: Preload scripts must use CommonJS when sandbox is enabled, as they run
+ * in a special isolated context that doesn't support native ES modules.
  */
 
 const { contextBridge, ipcRenderer } = require('electron');
diff --git a/electron/services/ConnectionManager.js b/electron/services/ConnectionManager.js
index 30819623..fa6007f4 100644
--- a/electron/services/ConnectionManager.js
+++ b/electron/services/ConnectionManager.js
@@ -5,8 +5,8 @@
  * Handles CRUD operations, active connection tracking, and general storage.
  */
 
-const Store = require('electron-store');
-const { randomUUID } = require('crypto');
+import Store from 'electron-store';
+import { randomUUID } from 'crypto';
 
 class ConnectionManager {
   constructor() {
@@ -220,4 +220,4 @@ class ConnectionManager {
   }
 }
 
-module.exports = ConnectionManager;
+export default ConnectionManager;
diff --git a/electron/services/MDNSDiscovery.js b/electron/services/MDNSDiscovery.js
index 8ff0f55c..58f27eb5 100644
--- a/electron/services/MDNSDiscovery.js
+++ b/electron/services/MDNSDiscovery.js
@@ -5,7 +5,8 @@
  * Requires servers to advertise themselves via Bonjour/Zeroconf.
  */
 
-const { Bonjour } = require('bonjour-service');
+import { Bonjour } from 'bonjour-service';
+import VersionChecker from './VersionChecker.js';
 
 class MDNSDiscovery {
   /**
@@ -72,8 +73,6 @@ class MDNSDiscovery {
    * @returns {Promise<Array>} Array of servers with version compatibility info
    */
   static async discoverServersWithVersionCheck(clientVersion, timeout = 5000) {
-    const VersionChecker = require('./VersionChecker');
-
     // First, discover all servers
     const servers = await MDNSDiscovery.discoverServers(timeout);
 
@@ -109,4 +108,4 @@ class MDNSDiscovery {
   }
 }
 
-module.exports = MDNSDiscovery;
+export default MDNSDiscovery;
diff --git a/electron/services/VersionChecker.js b/electron/services/VersionChecker.js
index 3561f8bc..ffc55fab 100644
--- a/electron/services/VersionChecker.js
+++ b/electron/services/VersionChecker.js
@@ -13,8 +13,6 @@ class VersionChecker {
    * @returns {Promise<Object>} Result object with compatibility info
    */
   static async checkVersion(serverUrl, clientVersion) {
-    // Dynamic import for node-fetch (ES module)
-    const fetch = (await import('node-fetch')).default;
     const result = {
       compatible: false,
       serverVersion: null,
@@ -27,7 +25,7 @@ class VersionChecker {
       // Construct the health endpoint URL
       const healthUrl = `${serverUrl}/api/v1/health`;
 
-      // Fetch server health with timeout
+      // Fetch server health with timeout using native fetch (Node.js 18+)
       const controller = new AbortController();
       const timeoutId = setTimeout(() => controller.abort(), 5000); // 5 second timeout
 
@@ -116,4 +114,4 @@ class VersionChecker {
   }
 }
 
-module.exports = VersionChecker;
+export default VersionChecker;