feat:实现Windows系统通知功能

- 集成node-notifier实现跨平台系统通知
   - AI响应完成时自动弹出Windows Toast通知
   - 支持通知防抖机制，避免频繁弹窗
   - 添加通知配置项：启用/禁用、声音、超时时间
   - 移除VS Code内置弹窗，仅在系统通知失败时作为备用

package.json

@@ -49,6 +49,11 @@
         "command": "ic-coder.openVCDViewer",
         "title": "打开 VCD 波形查看器",
         "category": "IC Coder"
+      },
+      {
+        "command": "ic-coder.testNotification",
+        "title": "测试系统通知",
+        "category": "IC Coder"
       }
     ],
     "viewsContainers": {
@@ -86,7 +91,29 @@
         ],
         "priority": "default"
       }
-    ]
+    ],
+    "configuration": {
+      "title": "IC Coder",
+      "properties": {
+        "ic-coder.enableSystemNotification": {
+          "type": "boolean",
+          "default": true,
+          "description": "启用系统级通知（任务完成时显示操作系统通知）"
+        },
+        "ic-coder.notificationSound": {
+          "type": "boolean",
+          "default": true,
+          "description": "通知时播放系统声音"
+        },
+        "ic-coder.notificationTimeout": {
+          "type": "number",
+          "default": 10,
+          "minimum": 0,
+          "maximum": 60,
+          "description": "通知自动消失时间（秒），0 表示不自动消失"
+        }
+      }
+    }
   },
   "scripts": {
     "vscode:prepublish": "pnpm run package",
@@ -103,6 +130,7 @@
   "devDependencies": {
     "@types/mocha": "^10.0.10",
     "@types/node": "22.x",
+    "@types/node-notifier": "^8.0.5",
     "@types/vscode": "^1.80.0",
     "@vscode/test-cli": "^0.0.12",
     "@vscode/test-electron": "^2.5.2",
@@ -126,6 +154,7 @@
     "@wavedrom/doppler": "^1.14.0",
     "eventsource-parser": "^3.0.6",
     "iconv-lite": "^0.7.1",
+    "node-notifier": "^10.0.1",
     "onml": "^2.1.0",
     "style-mod": "^4.1.3",
     "vcd-stream": "^1.5.0",