feat: 添加应用图标

- SVG 图标设计：数据库 + Redis R 字母 + 连接节点
- 生成各尺寸 PNG (16-512px)
- electron-builder 配置图标路径
- 主进程窗口使用图标

package.json

@@ -22,6 +22,40 @@
     "build:linux": "npm run build && electron-builder --linux",
     "lint": "eslint . --ext .js,.jsx,.ts,.tsx,.vue --fix"
   },
+  "build": {
+    "appId": "com.jokul.jredis-desktop",
+    "productName": "JRedisDesktop",
+    "directories": {
+      "output": "release"
+    },
+    "files": [
+      "out/**/*",
+      "package.json"
+    ],
+    "linux": {
+      "target": [
+        "AppImage",
+        "deb"
+      ],
+      "icon": "build/icons",
+      "category": "Development"
+    },
+    "mac": {
+      "target": [
+        "dmg",
+        "zip"
+      ],
+      "icon": "build/icon.icns",
+      "category": "public.app-category.developer-tools"
+    },
+    "win": {
+      "target": [
+        "nsis",
+        "portable"
+      ],
+      "icon": "build/icon.ico"
+    }
+  },
   "dependencies": {
     "electron-store": "^11.0.2",
     "ioredis": "^5.7.0",