feat(sdk-core): ConfigFileReader 新增 assets/config/ 目录支持

对齐 RN SDK 的 src/assets/config/ 目录约定：
搜索顺序：config/config.xuqmconfig → config/*.xuqmconfig → xuqm/config.xuqm → xuqm/*.xuqmconfig
旧路径 assets/xuqm/ 保持兼容。

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

sdk-core/src/main/java/com/xuqm/sdk/internal/ConfigFileReader.kt

@@ -5,21 +5,24 @@ import android.util.Log
 import com.google.gson.Gson
 
 /**
- * Reads and decrypts the init config file from assets/xuqm/.
- * Looks for config.xuqm first, then falls back to any *.xuqmconfig file.
- * This is used by XuqmSDK.autoInitialize() and does NOT depend on sdk-license.
+ * Reads and decrypts the init config file from assets.
+ *
+ * 搜索顺序（对齐 RN SDK 的 src/assets/config/）：
+ *   1. assets/config/config.xuqmconfig 或 config.xuqm
+ *   2. assets/config/*.xuqmconfig（取第一个）
+ *   3. assets/xuqm/config.xuqm（旧路径兼容）
+ *   4. assets/xuqm/*.xuqmconfig（旧路径兼容）
  */
 internal object ConfigFileReader {
 
     private const val TAG = "XuqmSDK"
-    private const val CONFIG_PATH = "xuqm/config.xuqm"
-    private const val CONFIG_DIR = "xuqm"
+    private val CONFIG_DIRS = listOf("config", "xuqm")
     private val gson = Gson()
 
     fun read(context: Context): ConfigFile? {
         return try {
             val path = findConfigPath(context) ?: run {
-                Log.w(TAG, "No config file found in assets/$CONFIG_DIR/")
+                Log.w(TAG, "No config file found in assets/{config,xuqm}/")
                 return null
             }
             Log.d(TAG, "Reading config file: $path")
@@ -39,16 +42,23 @@ internal object ConfigFileReader {
     }
 
     private fun findConfigPath(context: Context): String? {
-        try {
-            context.assets.open(CONFIG_PATH).close()
-            return CONFIG_PATH
-        } catch (_: Exception) {
-            // Try downloaded filenames such as appName.xuqmconfig.
+        for (dir in CONFIG_DIRS) {
+            // 优先 config.xuqmconfig 或 config.xuqm
+            for (name in listOf("config.xuqmconfig", "config.xuqm")) {
+                val path = "$dir/$name"
+                try {
+                    context.assets.open(path).close()
+                    return path
+                } catch (_: Exception) { /* not found */ }
+            }
+            // 否则取第一个 .xuqmconfig
+            val found = runCatching {
+                context.assets.list(dir)
+                    ?.firstOrNull { it.endsWith(".xuqmconfig", ignoreCase = true) }
+                    ?.let { "$dir/$it" }
+            }.getOrNull()
+            if (found != null) return found
         }
-        return runCatching {
-            context.assets.list(CONFIG_DIR)
-                ?.firstOrNull { it.endsWith(".xuqmconfig", ignoreCase = true) }
-                ?.let { "$CONFIG_DIR/$it" }
-        }.getOrNull()
+        return null
     }
 }