Restructure solution layout by module

src/Scanner/StellaOps.Scanner.Worker/Processing/PollDelayStrategy.cs

@@ -0,0 +1,49 @@
+using System;
+
+using StellaOps.Scanner.Worker.Options;
+
+namespace StellaOps.Scanner.Worker.Processing;
+
+public sealed class PollDelayStrategy
+{
+    private readonly ScannerWorkerOptions.PollingOptions _options;
+    private TimeSpan _currentDelay;
+
+    public PollDelayStrategy(ScannerWorkerOptions.PollingOptions options)
+    {
+        _options = options ?? throw new ArgumentNullException(nameof(options));
+    }
+
+    public TimeSpan NextDelay()
+    {
+        if (_currentDelay == TimeSpan.Zero)
+        {
+            _currentDelay = _options.InitialDelay;
+            return ApplyJitter(_currentDelay);
+        }
+
+        var doubled = _currentDelay + _currentDelay;
+        _currentDelay = doubled < _options.MaxDelay ? doubled : _options.MaxDelay;
+        return ApplyJitter(_currentDelay);
+    }
+
+    public void Reset() => _currentDelay = TimeSpan.Zero;
+
+    private TimeSpan ApplyJitter(TimeSpan duration)
+    {
+        if (_options.JitterRatio <= 0)
+        {
+            return duration;
+        }
+
+        var maxOffset = duration.TotalMilliseconds * _options.JitterRatio;
+        if (maxOffset <= 0)
+        {
+            return duration;
+        }
+
+        var offset = (Random.Shared.NextDouble() * 2.0 - 1.0) * maxOffset;
+        var adjustedMs = Math.Max(0, duration.TotalMilliseconds + offset);
+        return TimeSpan.FromMilliseconds(adjustedMs);
+    }
+}