refactor(数据库): 优化数据模型并移除初始化脚本

- 删除 InitDatabase.cs 文件，将数据库初始化逻辑移至其他位置
- 为 Portfolio、Position 和 Transaction 类添加索引
- 添加 AssetType 字段以支持多种资产类型
- 将 Shares 和 Amount 字段类型从 int 改为 decimal(18,8)

AssetManager.Data/InitDatabase.cs

@@ -1,46 +0,0 @@
-using SqlSugar;
-
-namespace AssetManager.Data;
-
-public class InitDatabase
-{
-    public static void Main()
-    {
-        var db = SqlSugarConfig.GetSqlSugarClient();
-        
-        try
-        {
-            db.CodeFirst.InitTables(
-                typeof(User),
-                typeof(Strategy),
-                typeof(Portfolio)
-            );
-            
-            Console.WriteLine("数据库表创建成功！");
-            
-            InsertSampleData(db);
-        }
-        catch (Exception ex)
-        {
-            Console.WriteLine($"数据库初始化失败: {ex.Message}");
-        }
-    }
-    
-    private static void InsertSampleData(ISqlSugarClient db)
-    {
-        var now = DateTime.Now;
-        
-        db.Insertable(new Strategy
-        {
-            Id = "hfea",
-            UserId = "system",
-            Alias = "HFEA 风险平价策略",
-            Type = "risk_parity",
-            Config = "{\"cycle\": \"quarter\", \"threshold\": 0.05, \"allocation\": {\"UPRO\": 0.6, \"TMF\": 0.4}}\n",
-            CreatedAt = now,
-            UpdatedAt = now
-        }).ExecuteCommand();
-        
-        Console.WriteLine("示例数据插入成功！");
-    }
-}

AssetManager.Data/Portfolio.cs

@@ -17,13 +17,13 @@ public class Portfolio
     /// <summary>
     /// 所属用户ID
     /// </summary>
-    [SugarColumn(ColumnName = "user_id")]
+    [SugarColumn(ColumnName = "user_id", IndexGroupNameList = new string[] { "idx_user_id" })]
     public string UserId { get; set; }
     
     /// <summary>
     /// 所用策略ID
     /// </summary>
-    [SugarColumn(ColumnName = "strategy_id")]
+    [SugarColumn(ColumnName = "strategy_id", IndexGroupNameList = new string[] { "idx_strategy_id" })]
     public string StrategyId { get; set; }
     
     /// <summary>
@@ -84,7 +84,7 @@ public class Position
     /// <summary>
     /// 所属组合ID
     /// </summary>
-    [SugarColumn(ColumnName = "portfolio_id")]
+    [SugarColumn(ColumnName = "portfolio_id", IndexGroupNameList = new string[] { "idx_portfolio_id" })]
     public string PortfolioId { get; set; }
     
     /// <summary>
@@ -99,11 +99,17 @@ public class Position
     [SugarColumn(ColumnName = "stock_name", Length = 200)]
     public string StockName { get; set; }
     
+    /// <summary>
+    /// 资产类型 (Stock/Crypto)
+    /// </summary>
+    [SugarColumn(ColumnName = "asset_type", Length = 20)]
+    public string AssetType { get; set; }
+    
     /// <summary>
     /// 持有数量
     /// </summary>
-    [SugarColumn(ColumnName = "shares")]
-    public int Shares { get; set; }
+    [SugarColumn(ColumnName = "shares", ColumnDataType = "decimal(18,8)")]
+    public decimal Shares { get; set; }
     
     /// <summary>
     /// 持仓均价
@@ -145,7 +151,7 @@ public class Transaction
     /// <summary>
     /// 所属组合ID
     /// </summary>
-    [SugarColumn(ColumnName = "portfolio_id")]
+    [SugarColumn(ColumnName = "portfolio_id", IndexGroupNameList = new string[] { "idx_portfolio_id" })]
     public string PortfolioId { get; set; }
     
     /// <summary>
@@ -160,6 +166,12 @@ public class Transaction
     [SugarColumn(ColumnName = "stock_code", Length = 50)]
     public string StockCode { get; set; }
     
+    /// <summary>
+    /// 资产类型 (Stock/Crypto)
+    /// </summary>
+    [SugarColumn(ColumnName = "asset_type", Length = 20)]
+    public string AssetType { get; set; }
+    
     /// <summary>
     /// 交易标题 (如: 定期定投)
     /// </summary>
@@ -169,8 +181,8 @@ public class Transaction
     /// <summary>
     /// 交易数量
     /// </summary>
-    [SugarColumn(ColumnName = "amount")]
-    public int Amount { get; set; }
+    [SugarColumn(ColumnName = "amount", ColumnDataType = "decimal(18,8)")]
+    public decimal Amount { get; set; }
     
     /// <summary>
     /// 成交价格