feat: 添加腾讯财经历史K线数据接口

- 新增 GetStockHistoricalFromTencentAsync 方法
- 腾讯财经历史数据免费无限制，解决 Tiingo 429 限流问题
- 获取历史数据时优先使用腾讯财经，失败后降级 Tiingo
- 支持日/周/月K线数据
- 数据格式: [日期, 开盘, 收盘, 最高, 最低, 成交量]

AssetManager.Infrastructure/Services/MarketDataService.cs

@@ -1,6 +1,7 @@
 using System.Net.Http.Json;
 using System.Security.Cryptography;
 using System.Text;
+using System.Text.Json;
 using System.Text.RegularExpressions;
 using AssetManager.Data;
 using AssetManager.Models.DTOs;
@@ -202,7 +203,7 @@ public class MarketDataService : IMarketDataService
     }
 
     /// <summary>
-    /// 获取股票历史数据
+    /// 获取股票历史数据（优先使用腾讯财经，免费无限制）
     /// </summary>
     /// <param name="symbol">股票代码</param>
     /// <param name="timeframe">时间周期</param>
@@ -212,15 +213,137 @@ public class MarketDataService : IMarketDataService
     {
         try
         {
-            _logger.LogInformation($"Requesting stock historical data for symbol: {symbol}, timeframe: {timeframe}, limit: {limit}");
+            // 优先使用腾讯财经（免费无限制）
+            var tencentData = await GetStockHistoricalFromTencentAsync(symbol, timeframe, limit);
+            if (tencentData.Any())
+            {
+                return tencentData;
+            }
+        }
+        catch (Exception ex)
+        {
+            _logger.LogWarning(ex, "腾讯财经历史数据获取失败，降级使用 Tiingo: {Symbol}", symbol);
+        }
+
+        // 降级使用 Tiingo
+        return await GetStockHistoricalFromTiingoAsync(symbol, timeframe, limit);
+    }
+
+    /// <summary>
+    /// 从腾讯财经获取历史K线数据
+    /// </summary>
+    private async Task<List<MarketDataResponse>> GetStockHistoricalFromTencentAsync(string symbol, string timeframe, int limit)
+    {
+        try
+        {
+            _logger.LogInformation("获取腾讯财经历史数据: {Symbol}", symbol);
+
+            // 注册GBK编码支持
+            Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
+
+            // 腾讯财经K线接口
+            // us{symbol} 表示美股，day/week/month 表示日/周/月K线
+            var klineType = timeframe switch
+            {
+                "1d" or "daily" => "day",
+                "1w" or "weekly" => "week",
+                "1M" or "monthly" => "month",
+                _ => "day"
+            };
+
+            var url = $"http://web.ifzq.gtimg.cn/appstock/app/fqkline/get?_var=kline_{klineType}qfq&param=us{symbol.ToUpper()},{klineType},,{Math.Min(limit, 320)}&qrcode=1&asrd=1";
+            
+            var responseBytes = await _httpClient.GetByteArrayAsync(url);
+            var response = Encoding.GetEncoding("GBK").GetString(responseBytes);
+
+            if (string.IsNullOrEmpty(response) || !response.Contains("kline"))
+            {
+                _logger.LogWarning("腾讯财经返回无效数据: {Symbol}", symbol);
+                return new List<MarketDataResponse>();
+            }
+
+            // 解析JSON
+            var jsonStart = response.IndexOf('{');
+            if (jsonStart < 0) return new List<MarketDataResponse>();
+            
+            var jsonStr = response.Substring(jsonStart);
+            var jsonDoc = JsonDocument.Parse(jsonStr);
+            var root = jsonDoc.RootElement;
+
+            // 数据路径: data -> us{symbol} -> qfq -> {klineType}
+            var dataPath = $"us{symbol.ToUpper()}";
+            if (!root.TryGetProperty("data", out var data) ||
+                !data.TryGetProperty(dataPath, out var stockData) ||
+                !stockData.TryGetProperty("qfq", out var qfq))
+            {
+                _logger.LogWarning("腾讯财经数据结构异常: {Symbol}", symbol);
+                return new List<MarketDataResponse>();
+            }
+
+            if (!qfq.TryGetProperty(klineType, out var klineData) || klineData.ValueKind != JsonValueKind.Array)
+            {
+                _logger.LogWarning("腾讯财经无K线数据: {Symbol}", symbol);
+                return new List<MarketDataResponse>();
+            }
+
+            var result = new List<MarketDataResponse>();
+            foreach (var item in klineData.EnumerateArray())
+            {
+                // 数据格式: [日期, 开盘, 收盘, 最高, 最低, 成交量]
+                var arr = item.EnumerateArray().ToList();
+                if (arr.Count < 6) continue;
+
+                var dateStr = arr[0].GetString();
+                if (!DateTime.TryParse(dateStr, out var date)) continue;
+
+                var open = arr[1].GetDecimal();
+                var close = arr[2].GetDecimal();
+                var high = arr[3].GetDecimal();
+                var low = arr[4].GetDecimal();
+                var volume = arr[5].GetDecimal();
+
+                if (close <= 0) continue;
+
+                result.Add(new MarketDataResponse
+                {
+                    Symbol = symbol,
+                    Open = open,
+                    High = high,
+                    Low = low,
+                    Close = close,
+                    Volume = volume,
+                    Timestamp = date,
+                    AssetType = "Stock"
+                });
+            }
+
+            // 按日期排序
+            result = result.OrderBy(x => x.Timestamp).TakeLast(limit).ToList();
+            _logger.LogInformation("腾讯财经获取 {Symbol} 历史数据 {Count} 条", symbol, result.Count);
+            
+            return result;
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "腾讯财经历史数据解析失败: {Symbol}", symbol);
+            return new List<MarketDataResponse>();
+        }
+    }
+
+    /// <summary>
+    /// 从 Tiingo 获取历史数据（降级方案）
+    /// </summary>
+    private async Task<List<MarketDataResponse>> GetStockHistoricalFromTiingoAsync(string symbol, string timeframe, int limit)
+    {
+        try
+        {
+            _logger.LogInformation($"Requesting stock historical data from Tiingo: {symbol}");
 
             var endDate = DateTime.UtcNow;
             var startDate = CalculateStartDate(endDate, timeframe, limit);
 
-            // Tiingo 历史数据端点（和示例一致）
             var url = $"https://api.tiingo.com/tiingo/daily/{symbol}/prices?startDate={startDate:yyyy-MM-dd}&endDate={endDate:yyyy-MM-dd}&token={_tiingoApiKey}";
             
-            // 使用带重试的请求
             var response = await GetWithRetryAsync(url);
             var data = await response.Content.ReadFromJsonAsync<List<TiingoDailyResponse>>();
 
@@ -229,8 +352,7 @@ public class MarketDataService : IMarketDataService
                 return new List<MarketDataResponse>();
             }
 
-            // 取最近 limit 条
+            return data
-            var result = data
                 .OrderByDescending(x => x.date)
                 .Take(limit)
                 .OrderBy(x => x.date)
@@ -246,12 +368,10 @@ public class MarketDataService : IMarketDataService
                     AssetType = "Stock"
                 })
                 .ToList();
-
-            return result;
         }
         catch (Exception ex)
         {
-            _logger.LogError(ex, $"Error getting stock historical data for {symbol}");
+            _logger.LogError(ex, "Tiingo 历史数据获取失败: {Symbol}", symbol);
             throw;
         }
     }