feat(core): 添加权限请求工具类并优化消息气泡布局

- 新增 PermissionUtil 工具类，用于检查和请求权限
- 修改 AgentController，引入 PermissionUtil
- 调整 MessageBubble 布局，优化 AI 消息显示

lib/core/utils/permission_util.dart

@@ -0,0 +1,134 @@
+import 'package:flutter/material.dart';
+import 'package:get/get.dart';
+import 'package:permission_handler/permission_handler.dart';
+import 'package:app_settings/app_settings.dart';
+
+class PermissionUtil {
+  /// 检查并请求多个权限
+  ///
+  /// [permissions] 要检查的权限列表，如 [Permission.microphone, Permission.location]
+  /// [rationaleTitle] 弹窗标题
+  /// [rationaleMessage] 权限用途说明内容（支持多行）
+  ///
+  /// 返回是否所有权限都已被授予
+  static Future<bool> checkAndRequestPermissions({
+    required List<Permission> permissions,
+    required String rationaleTitle,
+    required List<String> rationaleMessage,
+  }) async {
+    try {
+      Map<Permission, PermissionStatus> statuses = {};
+
+      // 检查是否都已授权
+      bool allGranted = true;
+      for (var permission in permissions) {
+        final status = await permission.status;
+        if (!status.isGranted) {
+          allGranted = false;
+          statuses[permission] = status;
+        }
+      }
+
+      if (allGranted) return true;
+
+      // 判断是否包含永久拒绝
+      bool hasPermanentDenied =
+          statuses.values.any((status) => status.isPermanentlyDenied);
+
+      // 显示提示弹窗
+      _showPermissionDialog(
+        isPermanent: hasPermanentDenied,
+        title: rationaleTitle,
+        messages: rationaleMessage,
+        onConfirm: () async {
+          if (hasPermanentDenied) {
+            AppSettings.openAppSettings();
+          } else {
+            final newStatuses = await permissions.request();
+            final allGrantedNow =
+                newStatuses.values.every((status) => status.isGranted);
+            if (!allGrantedNow) {
+              print("部分权限被拒绝: $newStatuses");
+            }
+          }
+        },
+      );
+
+      return false;
+    } catch (e) {
+      print("权限检查异常: $e");
+      return false;
+    }
+  }
+
+  /// 权限说明弹窗
+  static void _showPermissionDialog({
+    required bool isPermanent,
+    required String title,
+    required List<String> messages,
+    required VoidCallback onConfirm,
+  }) {
+    Get.generalDialog(
+      barrierDismissible: false,
+      barrierLabel: '权限提示',
+      transitionBuilder: (context, anim1, anim2, child) {
+        return SlideTransition(
+          position: Tween<Offset>(
+            begin: Offset(0, -1),
+            end: Offset(0, 0),
+          ).animate(CurvedAnimation(parent: anim1, curve: Curves.easeOut)),
+          child: child,
+        );
+      },
+      pageBuilder: (context, anim1, anim2) {
+        return SafeArea(
+          child: Align(
+            alignment: Alignment.topCenter,
+            child: Padding(
+              padding: const EdgeInsets.only(top: 80, left: 24, right: 24),
+              child: Material(
+                borderRadius: BorderRadius.circular(12),
+                color: Colors.white,
+                child: Padding(
+                  padding: const EdgeInsets.all(16),
+                  child: Column(
+                    mainAxisSize: MainAxisSize.min,
+                    crossAxisAlignment: CrossAxisAlignment.start,
+                    children: [
+                      Text(title,
+                          style: TextStyle(
+                              fontSize: 18, fontWeight: FontWeight.bold)),
+                      const SizedBox(height: 12),
+                      ...messages.map((msg) => Padding(
+                            padding: const EdgeInsets.only(bottom: 8),
+                            child: Text("• $msg"),
+                          )),
+                      const SizedBox(height: 20),
+                      Row(
+                        mainAxisAlignment: MainAxisAlignment.end,
+                        children: [
+                          TextButton(
+                            onPressed: () => Get.back(),
+                            child: const Text('取消'),
+                          ),
+                          const SizedBox(width: 8),
+                          TextButton(
+                            onPressed: () {
+                              Get.back();
+                              onConfirm();
+                            },
+                            child: Text(isPermanent ? '前往设置' : '授权'),
+                          ),
+                        ],
+                      ),
+                    ],
+                  ),
+                ),
+              ),
+            ),
+          ),
+        );
+      },
+    );
+  }
+}

lib/modules/agent/controllers/agent_controller.dart

@@ -16,6 +16,7 @@ import 'package:app_settings/app_settings.dart';
 import 'package:deep_voice/core/utils/logger.dart';
 import 'package:path_provider/path_provider.dart';
 import 'package:photo_view/photo_view.dart';
+import '../../../core/utils/permission_util.dart';
 
 class Message {
   final bool isUser; //标识信息是否来自用户还是AI

lib/modules/agent/views/message_bubble.dart

@@ -91,7 +91,7 @@ class MessageBubble extends GetView<AgentController> {
                   Row(
                     mainAxisAlignment: isUser
                         ? MainAxisAlignment.end
-                        : MainAxisAlignment.start,
+                        : MainAxisAlignment.spaceBetween,
                     children: [
                       // 时间戳（左对齐或右对齐）
                       Text(
@@ -104,7 +104,6 @@ class MessageBubble extends GetView<AgentController> {
                           fontWeight: FontWeight.w400,
                         ),
                       ),
-                      const Spacer(),
                       // AI标识（仅在AI消息时显示）
                       if (!isUser)
                         Padding(