Phase 8D: universal deployment package (XP + Win10/11, two entry points)

One RIOJoy-<ver>.zip now deploys on both OS generations (~75 MB with the
offline XP prerequisites):
- Layout: RIOJoy\app (net48 x64) + RIOJoy\app-xp (net40 x86) +
  RIOJoy\vendor (ViGEmBus; vendor\xp: .NET 4.0 offline installer +
  KB2468871, both signature-verified; RioGamepadXP driver slots in when
  8B lands - build warns/skips until then).
- RIOJoy\install-core.bat: shared OS-detecting install logic (ver ->
  5.1 = XP); pure cmd.exe on the XP path, delegates to install-rio.ps1
  on 10/11. Exports RIOJOY_APPDIR for shortcut creation.
- postinstall.bat (TeslaConsole, unattended): elevates, runs the core,
  then deletes install.bat + README.txt so C:\games stays clean.
- install.bat (standalone computers): same core + Start Menu/desktop
  shortcuts via make-shortcut.vbs (XP-safe); keeps the README.
- README.txt at the zip root explains which entry point to run.
- deploy *.ps1 re-encoded UTF-8-with-BOM: Windows PowerShell read the
  BOM-less files as ANSI, where an em-dash byte parses as a curly quote
  and breaks string parsing (bit install-rio.ps1 in dry-run testing).

Verified: zip layout correct; extracted package dispatch-tested on
Win10 non-elevated (OS detect -> modern route -> admin guard, system
untouched).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

deploy/install.bat

@@ -0,0 +1,54 @@
+@echo off
+rem ===========================================================================
+rem  RIOJoy standalone install entry point - for a computer WITHOUT the
+rem  TeslaConsole launcher. Extract the whole zip somewhere permanent (e.g.
+rem  C:\games), then run this as administrator. Installs the prerequisites
+rem  for this Windows version (XP or 10/11) via the shared install core and
+rem  creates Start Menu + desktop shortcuts to the right flavor of the app.
+rem  Nothing auto-starts: launch RIOJoy from the shortcut when you want it.
+rem  See README.txt for details.
+rem ===========================================================================
+setlocal
+title RIOJoy install
+
+rem --- elevate if we are not already administrator --------------------------
+net session >nul 2>&1
+if %errorlevel% neq 0 (
+    rem "if errorlevel" evaluates at run time (a %var% here would be stale).
+    ver | findstr /C:"Version 5.1" >nul
+    if not errorlevel 1 (
+        echo This installer must run as an Administrator user.
+        pause
+        exit /b 1
+    )
+    echo Requesting administrator privileges...
+    powershell -NoProfile -Command "Start-Process -FilePath '%~f0' -Verb RunAs"
+    exit /b 0
+)
+
+cd /d "%~dp0"
+
+call "%~dp0RIOJoy\install-core.bat"
+set RC=%errorlevel%
+if %RC% neq 0 goto done
+
+rem --- shortcuts (Start Menu + desktop) --------------------------------------
+rem RIOJOY_APPDIR is set by install-core.bat to app (modern) or app-xp (XP).
+set EXE=%RIOJOY_APPDIR%\RioJoy.Tray.exe
+if not exist "%EXE%" (
+    echo ERROR: app executable not found: %EXE%
+    set RC=1
+    goto done
+)
+echo Creating shortcuts...
+cscript //nologo "%~dp0RIOJoy\make-shortcut.vbs" "%EXE%" "RIOJoy" "%RIOJOY_APPDIR%"
+
+:done
+echo.
+if %RC% neq 0 (
+    echo install FAILED with exit code %RC%.
+) else (
+    echo install completed. Launch RIOJoy from the Start Menu or desktop shortcut.
+)
+pause
+exit /b %RC%