feat(sdk-core): XuqmSDK.initialize() 新增 serverUrl 参数支持私有化部署

传入 serverUrl 后 SDK 自动完成：
- 配置所有服务端点（controlBaseUrl/fileBaseUrl/imApiBaseUrl/imWsUrl/pushBaseUrl/updateBaseUrl）
- 通过反射调用 LicenseSDK.initialize() 注入私有化 appKey 和 baseUrl
- wss/ws scheme 自动根据 https/http 推导

App 侧只需：
  XuqmSDK.initialize(context, appKey, serverUrl = "https://your-server.com", logLevel = WARN)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

sdk-core/src/main/java/com/xuqm/sdk/XuqmSDK.kt

@@ -30,6 +30,7 @@ object XuqmSDK {
     fun initialize(
         context: Context,
         appKey: String,
+        serverUrl: String? = null,
         logLevel: LogLevel = LogLevel.WARN,
     ) {
         val applicationContext = context.applicationContext
@@ -48,6 +49,35 @@ object XuqmSDK {
             initializedAppKey = appKey
             initialized = true
         }
+        serverUrl?.takeIf { it.isNotBlank() }?.let { configurePrivateServer(context, appKey, it) }
+    }
+
+    private fun configurePrivateServer(context: Context, appKey: String, serverUrl: String) {
+        val base = serverUrl.trimEnd('/') + "/"
+        val wsBase = serverUrl.trimEnd('/')
+            .replace("https://", "wss://")
+            .replace("http://", "ws://")
+        configureServiceEndpoints(
+            ServiceEndpoints(
+                controlBaseUrl = base,
+                fileBaseUrl = base,
+                imApiBaseUrl = base,
+                imWsUrl = "$wsBase/ws/im",
+                pushBaseUrl = base,
+                updateBaseUrl = base,
+            )
+        )
+        // Initialize LicenseSDK via reflection — sdk-core cannot depend on sdk-license
+        runCatching {
+            val clazz = Class.forName("com.xuqm.sdk.license.LicenseSDK")
+            val instance = clazz.getField("INSTANCE").get(null)
+            val method = clazz.methods.firstOrNull { m ->
+                m.name == "initialize" &&
+                    m.parameterTypes.size == 4 &&
+                    m.parameterTypes[3] == String::class.java
+            }
+            method?.invoke(instance, context.applicationContext, appKey, null, base)
+        }
     }
 
     fun configureServiceEndpoints(endpoints: ServiceEndpoints) {