Seed filter slot names from hardware during ZWO EFW discovery

ListDevice now accepts an optional seedQueryParams delegate to extract
extra URI query params while the device is briefly open during discovery.
For EFW devices, this seeds filter1=Filter 1&...&filterN=Filter N from
the hardware NumberOfSlots, giving the equipment tab the correct slot
count immediately without requiring a full connect.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: sebgod

src/TianWen.Lib/Devices/ZWO/ZWODeviceSource.cs

@@ -68,32 +68,48 @@ public IEnumerable<ZWODevice> RegisteredDevices(DeviceType deviceType)
 
     static IEnumerable<ZWODevice> ListEAFs() => ListDevice<EAF_INFO>(DeviceType.Focuser);
 
-    static IEnumerable<ZWODevice> ListEFWs() => ListDevice<EFW_INFO>(DeviceType.FilterWheel);
+    static IEnumerable<ZWODevice> ListEFWs() => ListDevice<EFW_INFO>(DeviceType.FilterWheel, SeedFilterParams);
 
-    static IEnumerable<ZWODevice> ListDevice<TDeviceInfo>(DeviceType deviceType) where TDeviceInfo : struct, INativeDeviceInfo
+    /// <summary>
+    /// Builds query params seeding default filter names from the hardware slot count
+    /// (available while the EFW is open during discovery).
+    /// </summary>
+    private static string? SeedFilterParams(EFW_INFO efwInfo)
+    {
+        var slotCount = efwInfo.NumberOfSlots;
+        if (slotCount <= 0)
+        {
+            return null;
+        }
+
+        var parts = new string[slotCount];
+        for (var i = 0; i < slotCount; i++)
+        {
+            parts[i] = $"{DeviceQueryKeyExtensions.FilterKey(i + 1)}={Uri.EscapeDataString($"Filter {i + 1}")}";
+        }
+        return string.Join("&", parts);
+    }
+
+    static IEnumerable<ZWODevice> ListDevice<TDeviceInfo>(DeviceType deviceType, Func<TDeviceInfo, string?>? seedQueryParams = null) where TDeviceInfo : struct, INativeDeviceInfo
     {
         var ids = new HashSet<int>();
 
-        var cameraIterator = new DeviceIterator<TDeviceInfo>();
+        var iterator = new DeviceIterator<TDeviceInfo>();
 
-        foreach (var deviceInfo in cameraIterator)
+        foreach (var deviceInfo in iterator)
         {
             if (!ids.Contains(deviceInfo.ID) && deviceInfo.Open())
             {
                 try
                 {
-                    if (deviceInfo.SerialNumber is { Length: > 0 } serialNumber)
-                    {
-                        yield return new ZWODevice(deviceType, serialNumber, deviceInfo.Name);
-                    }
-                    else if (deviceInfo.IsUSB3Device && deviceInfo.CustomId is { Length: > 0 } customId)
-                    {
-                        yield return new ZWODevice(deviceType, customId, deviceInfo.Name);
-                    }
-                    else
-                    {
-                        yield return new ZWODevice(deviceType, deviceInfo.Name, deviceInfo.Name);
-                    }
+                    var deviceId = deviceInfo.SerialNumber is { Length: > 0 } sn ? sn
+                        : deviceInfo.IsUSB3Device && deviceInfo.CustomId is { Length: > 0 } cid ? cid
+                        : deviceInfo.Name;
+
+                    var extraQuery = seedQueryParams?.Invoke(deviceInfo);
+                    var queryPart = extraQuery is { Length: > 0 } ? $"?{extraQuery}" : "";
+                    var uri = new Uri($"{deviceType}://{typeof(ZWODevice).Name}/{deviceId}{queryPart}#{deviceInfo.Name}");
+                    yield return new ZWODevice(uri);
 
                     ids.Add(deviceInfo.ID);
                 }