build: add Windows NSIS installer via electron-builder

Co-authored-by: Cursor <cursoragent@cursor.com>

package.json

@@ -8,9 +8,41 @@
   "scripts": {
     "dev": "node src/run-electron.mjs",
     "start": "node src/run-electron.mjs",
-    "test": "node --test src/release/*.test.mjs"
+    "test": "node --test src/release/*.test.mjs",
+    "pack:win": "electron-builder --win",
+    "pack:dir": "electron-builder --dir"
   },
-  "dependencies": {
-    "electron": "^41.2.0"
+  "dependencies": {},
+  "devDependencies": {
+    "electron": "^41.2.0",
+    "electron-builder": "^26.8.1"
+  },
+  "build": {
+    "appId": "com.ttrpgplayer.publisher",
+    "productName": "TTRPG Player Publisher",
+    "copyright": "Copyright © TTRPGPlayer",
+    "directories": {
+      "output": "release"
+    },
+    "files": [
+      "src/**/*",
+      "default-config.json",
+      "package.json"
+    ],
+    "asar": true,
+    "win": {
+      "target": [
+        {
+          "target": "nsis",
+          "arch": ["x64"]
+        }
+      ],
+      "artifactName": "TTRPGPlayerPublisher-Setup.${ext}"
+    },
+    "nsis": {
+      "oneClick": false,
+      "allowToChangeInstallationDirectory": true,
+      "artifactName": "TTRPGPlayerPublisher-Setup.${ext}"
+    }
   }
 }