chore: 统一代码风格

src/Core/Database.cs

@@ -298,7 +298,7 @@ public static class Database
     private static readonly HashSet<string> AllowedSortColumns = new(StringComparer.OrdinalIgnoreCase)
     {
         "filename", "duration", "sample_rate", "channels",
-        "date_added", "rating", "type", "category", "id"
+        "date_added", "rating", "type", "category", "id",
     };
 
     /// <summary>
@@ -483,12 +483,12 @@ public static class Database
         using IDbConnection connection = GetConnection();
         connection.Open();
         const string sql = "SELECT keywords FROM audio_files WHERE keywords IS NOT NULL AND keywords != '';";
-        var rows = connection.Query<string>(sql);
-        var allKeywords = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
-        foreach (var row in rows)
+        IEnumerable<string> rows = connection.Query<string>(sql);
+        HashSet<string> allKeywords = new(StringComparer.OrdinalIgnoreCase);
+        foreach (string row in rows)
         {
             if (string.IsNullOrWhiteSpace(row)) continue;
-            foreach (var part in row.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries))
+            foreach (string part in row.Split(',', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries))
             {
                 if (!string.IsNullOrWhiteSpace(part))
                     allKeywords.Add(part);

src/Core/PreferencesManager.cs

@@ -28,7 +28,7 @@ public static class PreferencesManager
         // 文件不存在或反序列化失败 → 创建默认实例
         CurrentPreferences = new Preferences
         {
-            DatabasePath = GetDefaultDatabasePath()
+            DatabasePath = GetDefaultDatabasePath(),
         };
 
         // 立即落盘，确保下次启动能直接读取