fix: handle db exceptions in auth

@@ -53,16 +53,28 @@ class AuthService
         }
 
         // 3. 查找或创建用户
-        $user = $this->findOrCreateUser($phone, $openid, $unionid);
+        try {
+            $user = $this->findOrCreateUser($phone, $openid, $unionid);
+        } catch (Exception $e) {
+            $this->logDebug("Exception in findOrCreateUser: " . $e->getMessage());
+            return ['ok' => false, 'error' => 'Database Error: ' . $e->getMessage()];
+        }
+
         if (!$user) {
-            $this->logDebug("Error: Failed to find/create user");
+            $this->logDebug("Error: Failed to find/create user (Result is null)");
             return ['ok' => false, 'error' => '用户创建失败'];
         }
 
         $this->logDebug("User ID: " . $user['id']);
 
         // 4. 创建 Session
-        $token = $this->createSession($user['id']);
+        try {
+            $token = $this->createSession($user['id']);
+        } catch (Exception $e) {
+            $this->logDebug("Exception in createSession: " . $e->getMessage());
+            return ['ok' => false, 'error' => 'Session Error: ' . $e->getMessage()];
+        }
+
         if (!$token) {
             $this->logDebug("Error: Failed to create session");
             return ['ok' => false, 'error' => 'Session 创建失败'];