test: raise the thread pool minimum to avoid starvation

Property tests saturate the pool while network tests wait on continuations,
so a loopback handshake could exceed its timeout and fail the run
intermittently. A higher floor removes the starvation.

tests/PalladiumWallet.Tests/ThreadPoolSetup.cs

@@ -0,0 +1,12 @@
+using System.Runtime.CompilerServices;
+
+namespace PalladiumWallet.Tests;
+
+internal static class ThreadPoolSetup
+{
+    // Property tests saturate the pool while network tests wait on continuations; with the
+    // default minimum the pool injects threads slowly and a loopback handshake can stall for
+    // seconds. A higher floor removes that starvation so the request timeouts stay meaningful.
+    [ModuleInitializer]
+    internal static void Init() => ThreadPool.SetMinThreads(256, 256);
+}