feat: 添加许可证密钥管理功能，更新许可证激活逻辑，支持环境变量配置，增加Docker支持

server/models/LicenseKey.js

@@ -0,0 +1,19 @@
+const mongoose = require('mongoose');
+
+const licenseKeySchema = new mongoose.Schema({
+    licenseKey: {
+        type: String,
+        required: true,
+        unique: true
+    },
+    isUsed: {
+        type: Boolean,
+        default: false
+    },
+    generatedAt: {
+        type: Date,
+        default: Date.now
+    }
+});
+
+module.exports = mongoose.model('LicenseKey', licenseKeySchema);