Phase 0 WP-0.1: Create .NET 10 solution structure with all 17 component projects

17 source projects (Commons + Host + 15 components) and 17 xUnit test projects.
SLNX format, net10.0, nullable enabled, warnings as errors. All components
reference Commons; Host references all components. Builds and tests clean.

tests/ScadaLink.Security.Tests/bin/Debug/net10.0/ScadaLink.Security.Tests.runtimeconfig.json

@@ -0,0 +1,13 @@
+{
+  "runtimeOptions": {
+    "tfm": "net10.0",
+    "framework": {
+      "name": "Microsoft.NETCore.App",
+      "version": "10.0.0"
+    },
+    "configProperties": {
+      "MSTest.EnableParentProcessQuery": true,
+      "System.Runtime.Serialization.EnableUnsafeBinaryFormatterSerialization": false
+    }
+  }
+}