fix: 增加页面HTML解析作为抖音直播状态检测备选方案，避免API格式变化导致误判未直播

src/LiveRecorder.Infrastructure/Platforms/Douyin/DouyinHttpClient.cs

@@ -61,6 +61,10 @@ public sealed class DouyinHttpClient
         "\"roomStore\":{[\\s\\S]*?\"roomInfo\":{[\\s\\S]*?\"anchor\":{[\\s\\S]*?\"nickname\":\"(?<nickname>[\\s\\S]*?)\"",
         RegexOptions.Compiled | RegexOptions.CultureInvariant);
 
+    private static readonly Regex HtmlStatusRegex = new(
+        "\"roomStore\":{[\\s\\S]*?\"roomInfo\":{[\\s\\S]*?\"room\":{[\\s\\S]*?\"status\":(?<status>\\d+)",
+        RegexOptions.Compiled | RegexOptions.CultureInvariant);
+
     private readonly PlatformHttpClientFactory _platformHttpClientFactory;
     private readonly IServiceScopeFactory _serviceScopeFactory;
     private readonly DouyinXBogusSigner _xBogusSigner;
@@ -129,6 +133,23 @@ public sealed class DouyinHttpClient
         return await JsonDocument.ParseAsync(stream, cancellationToken: cancellationToken);
     }
 
+    public static int? TryExtractLiveStatusIntFromHtml(string? html)
+    {
+        var normalized = TryExtractNormalizedStatePayload(html);
+        if (string.IsNullOrWhiteSpace(normalized))
+        {
+            return null;
+        }
+
+        var match = HtmlStatusRegex.Match(normalized);
+        if (match.Success && int.TryParse(match.Groups["status"].Value, out var status))
+        {
+            return status;
+        }
+
+        return null;
+    }
+
     public async Task<StreamInputHeaders> GetStreamInputHeadersAsync(string roomId, CancellationToken cancellationToken = default)
     {
         var settings = await GetSystemSettingsAsync(cancellationToken);

src/LiveRecorder.Infrastructure/Platforms/Douyin/DouyinLivePlatformAdapter.cs

@@ -103,9 +103,35 @@ public sealed class DouyinLivePlatformAdapter : ILivePlatformAdapter
         var coverUrl = GetCoverUrl(room);
 
         var isLive = statusCode == 2 || GetInt(room, "live_status") is 1 or 2;
+        if (!isLive)
+        {
+            var pageStatus = await TryDetectLiveStatusFromPageAsync(roomId, cancellationToken);
+            if (pageStatus is 1 or 2)
+            {
+                isLive = true;
+                statusCode ??= pageStatus;
+            }
+        }
+
         return new LiveStatusSnapshot(isLive, title, anchorName, anchorId, avatarUrl, coverUrl, statusCode, statusCode?.ToString());
     }
 
+    private async Task<int?> TryDetectLiveStatusFromPageAsync(string roomId, CancellationToken cancellationToken)
+    {
+        try
+        {
+            var (_, html) = await _douyinHttpClient.ResolvePageAsync(
+                $"https://live.douyin.com/{roomId}",
+                cancellationToken);
+
+            return DouyinHttpClient.TryExtractLiveStatusIntFromHtml(html);
+        }
+        catch
+        {
+            return null;
+        }
+    }
+
     public async Task<StreamUrlResult> GetStreamUrlAsync(
         string roomId,
         string? preferredQuality = null,