兴趣范围内有 200 个对象，也不能把它们全塞进同一帧快照

public sealed class ConnectionSnapshotOwner
{
    private long requestedGeneration;

    public SnapshotBatch Active { get; private set; } = SnapshotBatch.Empty;

    public long BeginRequest() => ++requestedGeneration;

    public SnapshotBatch BuildCandidate(
        long generation,
        int byteBudget,
        IEnumerable<EntityState> visible)
    {
        if (byteBudget < 0)
            throw new ArgumentOutOfRangeException(nameof(byteBudget));

        var selected = new List<int>();
        var usedBytes = 0;
        foreach (var entity in visible
                     .OrderByDescending(item => item.Priority)
                     .ThenBy(item => item.DistanceMeters)
                     .ThenBy(item => item.Id))
        {
            if (entity.EncodedBytes <= 0)
                throw new InvalidDataException($"invalid-size:{entity.Id}");

            if (usedBytes + entity.EncodedBytes > byteBudget)
                continue;

            selected.Add(entity.Id);
            usedBytes += entity.EncodedBytes;
        }

        return new SnapshotBatch(generation, selected, usedBytes);
    }

    public bool TryCommit(SnapshotBatch candidate, bool encodeSucceeded)
    {
        if (!encodeSucceeded || candidate.Generation != requestedGeneration)
            return false;

        Active = candidate;
        return true;
    }
}

$ dotnet build $WORK_DIR/.tmp/daily-labs/interest-budget/InterestBudgetProbe.csproj -c Release
Build succeeded.
0 Warning(s)
0 Error(s)
exit code: 0

$ dotnet run --project $WORK_DIR/.tmp/daily-labs/interest-budget/InterestBudgetProbe.csproj -c Release --no-build
SAMPLE budget=120 selected=[101,205,412] used=116 committed=True
FAILURE encode=false candidate=[101,205] committed=False active=[101,205,412]
RESULT passed=8 failed=0 skipped=0 elapsed_ms=49
exit code: 0