Update Electron main process for production readiness and app protocol handling

- Register `app://` protocol for secure file handling in production.
- Adjust icon paths to support macOS and Windows/Linux distinctions.
- Enhance security by validating file paths under the `out/` directory.
- Replace `file://` accesses with the `app://` protocol.
- Update `package.json` build scripts for platform-specific builds and refined output directory structure.
- Modify main and login window settings for improved compatibility across all platforms.

package.json

@@ -5,17 +5,11 @@
   "type": "module",
   "main": "dist/electron/main.js",
   "scripts": {
-    "dev:next": "next dev -p 4000",
-    "dev:electron": "NODE_ENV=development PORT=4000 electron -r tsx/cjs electron/main.ts",
-    "dev": "concurrently \"npm run dev:next\" \"wait-on http://localhost:4000 && npm run dev:electron\"",
-    "build:next": "next build",
-    "build:electron": "tsc --project tsconfig.electron.json && tsc --project tsconfig.preload.json",
-    "build": "npm run build:next && npm run build:electron",
-    "start": "electron .",
-    "package": "npm run build && electron-builder build --mac --win --linux",
-    "package:mac": "npm run build && electron-builder build --mac",
-    "package:win": "npm run build && electron-builder build --win",
-    "package:linux": "npm run build && electron-builder build --linux"
+    "dev": "concurrently \"next dev -p 4000\" \"wait-on http://localhost:4000 && electron -r tsx/cjs electron/main.ts\"",
+    "build:mac": "next build && tsc --project tsconfig.electron.json && tsc --project tsconfig.preload.json && electron-builder build --mac",
+    "build:win": "next build && tsc --project tsconfig.electron.json && tsc --project tsconfig.preload.json && electron-builder build --win",
+    "build:linux": "next build && tsc --project tsconfig.electron.json && tsc --project tsconfig.preload.json && electron-builder build --linux",
+    "build:all": "next build && tsc --project tsconfig.electron.json && tsc --project tsconfig.preload.json && electron-builder build --mac --win --linux"
   },
   "keywords": [],
   "author": "",
@@ -71,17 +65,22 @@
     "tailwindcss": "^4.1.17"
   },
   "build": {
-    "appId": "com.eritorsscribe.app",
-    "productName": "EritorsScribe",
+    "appId": "com.eritors.scribe.desktop",
+    "productName": "ERitors Scribe",
     "files": [
       "dist/**/*",
       "out/**/*",
+      "build/**/*",
       "package.json"
     ],
+    "asarUnpack": [
+      "out/**/*"
+    ],
     "directories": {
       "output": "release"
     },
     "mac": {
+      "icon": "build/icons/mac/icon.icns",
       "target": [
         "dmg",
         "zip"
@@ -93,6 +92,7 @@
       "entitlementsInherit": "build/entitlements.mac.plist"
     },
     "win": {
+      "icon": "build/icons/win/icon.ico",
       "target": [
         {
           "target": "nsis",
@@ -104,6 +104,7 @@
       ]
     },
     "linux": {
+      "icon": "build/icons/png",
       "target": [
         "AppImage",
         "deb"