Add per-module build scripts at repo root

build-launcher.bat: publishes PSLauncher.App only (Release single-file).
build-updater.bat:  publishes PSLauncher.Updater only.
build-all.bat:      both, sequentially, fast-fail on the first error.

All three pause at the end so a double-click from Explorer shows the
result before the window closes. The existing build-installer.bat
(launcher + updater + Inno Setup .exe) stays as the full release
pipeline.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

build-updater.bat

@@ -0,0 +1,24 @@
+@echo off
+REM Build de l'updater (PSLauncher.Updater.exe).
+REM Sortie : C:\ASTERION\GIT\PS_Launcher\PSLauncher.Updater.exe (~34 Mo single-file)
+REM L'updater accompagne PSLauncher.exe — il doit etre dans le meme dossier.
+
+setlocal
+set "REPO=%~dp0"
+echo.
+echo ==^> dotnet publish PSLauncher.Updater (Release single-file)
+echo.
+
+dotnet publish "%REPO%src\PSLauncher.Updater\PSLauncher.Updater.csproj" -c Release --nologo
+set "EXITCODE=%ERRORLEVEL%"
+
+echo.
+if %EXITCODE% NEQ 0 (
+    echo [ECHEC] Build de l'updater echoue avec le code %EXITCODE%.
+) else (
+    echo [OK] PSLauncher.Updater.exe disponible a la racine du repo :
+    echo      %REPO%PSLauncher.Updater.exe
+)
+echo.
+pause
+endlocal & exit /b %EXITCODE%