Phase 0: scaffold modern RIOJoy solution + plan

Modernization of the legacy vJoy-based RIO cockpit interface for Win10/11,
removing the vJoy dependency in favor of a custom VHF/UMDF HID driver,
rewritten in C#/.NET 8 as a background tray app with per-game profiles.

- Reorganize: legacy C++ -> legacy/, cockpit art -> docs/reference/
- RioJoy.sln: src/RioJoy.Core (lib) + src/RioJoy.Tray (tray app), net8.0-windows x64
- driver/ placeholder for the RioGamepad WDK driver
- docs/PLAN.md (7-phase plan; profiles + serial-yield model)
- docs/PROTOCOL.md (RIO wire format + iRIO input-map reference)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/RioJoy.Core/RioJoy.Core.csproj

@@ -0,0 +1,17 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <!-- net8.0 LTS. Windows-flavored TFM: this library uses Win32 P/Invoke
+         (SendInput, SystemParametersInfo) and System.IO.Ports. -->
+    <TargetFramework>net8.0-windows</TargetFramework>
+    <Platforms>x64</Platforms>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <LangVersion>latest</LangVersion>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="System.IO.Ports" Version="8.0.0" />
+  </ItemGroup>
+
+</Project>

src/RioJoy.Core/RioJoyInfo.cs

@@ -0,0 +1,17 @@
+namespace RioJoy.Core;
+
+/// <summary>
+/// Shared metadata for the RIOJoy runtime. The real domain types
+/// (RIO serial protocol, profile model, input mapper, virtual-HID feeder)
+/// land here in later phases; see docs/PLAN.md.
+/// </summary>
+public static class RioJoyInfo
+{
+    /// <summary>Product display name.</summary>
+    public const string Name = "RIOJoy";
+
+    /// <summary>
+    /// Successor to the legacy vJoy-based "RIOvJoy v.03" (see legacy/riovjoy2.cpp).
+    /// </summary>
+    public const string Version = "0.1.0-dev";
+}

src/RioJoy.Tray/Program.cs

@@ -0,0 +1,16 @@
+namespace RioJoy.Tray;
+
+internal static class Program
+{
+    /// <summary>
+    /// Entry point. RIOJoy runs as a background tray application with no main
+    /// window: an ApplicationContext owns the NotifyIcon and the runtime, so the
+    /// message loop stays alive while the only UI is the tray icon and its menu.
+    /// </summary>
+    [STAThread]
+    private static void Main()
+    {
+        ApplicationConfiguration.Initialize();
+        Application.Run(new TrayApplicationContext());
+    }
+}

src/RioJoy.Tray/RioJoy.Tray.csproj

@@ -0,0 +1,18 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFramework>net8.0-windows</TargetFramework>
+    <Platforms>x64</Platforms>
+    <Nullable>enable</Nullable>
+    <UseWindowsForms>true</UseWindowsForms>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <LangVersion>latest</LangVersion>
+    <ApplicationManifest>app.manifest</ApplicationManifest>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\RioJoy.Core\RioJoy.Core.csproj" />
+  </ItemGroup>
+
+</Project>

src/RioJoy.Tray/TrayApplicationContext.cs

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+namespace RioJoy.Tray;
+
+/// <summary>
+/// Owns the tray icon and (eventually) the RIOJoy runtime: the serial link to
+/// the RIO, the active profile, the virtual-HID feeder, and the profile
+/// auto-switch watcher.
+///
+/// Phase 0 scaffold: just the tray icon + a minimal menu. Wiring the runtime is
+/// Phase 5 work; the menu items below are placeholders that mirror the legacy
+/// console menu (reset/recalibrate axes, version/status, quit).
+/// </summary>
+internal sealed class TrayApplicationContext : ApplicationContext
+{
+    private readonly NotifyIcon _trayIcon;
+
+    public TrayApplicationContext()
+    {
+        var menu = new ContextMenuStrip();
+        menu.Items.Add("RIOJoy (scaffold)").Enabled = false;
+        menu.Items.Add(new ToolStripSeparator());
+        menu.Items.Add("Exit", null, (_, _) => ExitThread());
+
+        _trayIcon = new NotifyIcon
+        {
+            Icon = SystemIcons.Application,
+            Text = "RIOJoy",
+            Visible = true,
+            ContextMenuStrip = menu,
+        };
+    }
+
+    protected override void Dispose(bool disposing)
+    {
+        if (disposing)
+        {
+            _trayIcon.Visible = false;
+            _trayIcon.Dispose();
+        }
+
+        base.Dispose(disposing);
+    }
+}

src/RioJoy.Tray/app.manifest

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+<?xml version="1.0" encoding="utf-8"?>
+<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
+  <assemblyIdentity version="1.0.0.0" name="RioJoy.Tray.app" type="win32" />
+
+  <!-- Run as the invoking user. RIOJoy needs no admin rights for normal
+       operation: opening a COM port, calling SendInput, and DeviceIoControl
+       to the virtual-HID control device (whose security descriptor will allow
+       interactive users). Installing the driver is a separate, elevated step. -->
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
+    <security>
+      <requestedPrivileges>
+        <requestedExecutionLevel level="asInvoker" uiAccess="false" />
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+
+  <!-- Declare Windows 10/11 compatibility for correct DPI / API behavior. -->
+  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
+    <application>
+      <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" /> <!-- Windows 10/11 -->
+    </application>
+  </compatibility>
+</assembly>