case 4690 - build-release.bat: copy all output to build-output.txt; UTF-8 for MkDocs when piped

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

build-release.bat

@@ -1,3 +1,13 @@
+@rem Runs itself again with --logged so all output also goes to build-output.txt beside this script (overwritten each build, not in git)
+@if /i "%~1"=="--logged" goto LOGGED
+@powershell -NoProfile -ExecutionPolicy Bypass -Command "[Console]::OutputEncoding = [Text.Encoding]::UTF8; cmd /c '%~f0' --logged '2>&1' | Tee-Object -FilePath '%~dp0build-output.txt'"
+@pause
+@exit /b
+:LOGGED
+@chcp 65001 >nul
+rem mkdocs-material prints a warning banner MkDocs cannot write to a pipe without UTF-8
+set PYTHONUTF8=1
+
 set m=Unknown error
 
 @echo ****************** CLEAN ALL OUTPUT FOLDERS **********
@@ -158,7 +168,7 @@ echo.
 echo.
 echo Error:
 echo %m%
-pause
+rem the outer run pauses once the log is complete
 goto DONE
 
 ::------------------------
@@ -169,7 +179,6 @@ echo.
 echo.
 echo.
 @echo Completed without error
-pause
 
 
 :DONE