fix(installer): escape parentheses in launcher echoes so cmd doesn't mis-parse the block

The real cause of the "... / : was unexpected at this time." launch crash (exit 255, regressed by the
progress-message change in #60, only partly addressed by #71): the advisory
`echo   Starting the OpenClaw gateway (usually a few seconds)...` sits INSIDE the
`if not "!OPENCLAW_CMD!"=="" ( ... )` block, and its unescaped ( ) are counted by cmd as block
delimiters, breaking paren matching for the rest of the block. #71 removed the goto-in-parens but left
these parens, so it still crashed (now blaming "...").

Escape both launcher advisory echoes with ^( ^) — the same convention install_nulla.bat already uses
(e.g. ^(SearXNG^)). Verified in the real cmd parser: the block now parses, prints, loops, and gotos
with no error.

Author: Parad0x-Labs

OpenClaw_NULLA.bat

@@ -110,7 +110,7 @@ if "!LAUNCH_REQUESTED!"=="0" (
     exit /b 1
   )
 )
-echo   Waiting for the NULLA API to come up (one dot per second, up to ~2 min):
+echo   Waiting for the NULLA API to come up ^(one dot per second, up to ~2 min^):
 set "READY=0"
 for /L %%i in (1,1,120) do (
   if !READY! equ 0 (
@@ -141,7 +141,7 @@ if %errorlevel% neq 0 (
   if "!OPENCLAW_CMD!"=="" if exist "%USERPROFILE%\.local\bin\openclaw.cmd" set "OPENCLAW_CMD=%USERPROFILE%\.local\bin\openclaw.cmd"
   if not "!OPENCLAW_CMD!"=="" (
     "%PYTHON_EXE%" "%SCRIPT_ROOT%\installer\start_windows_detached.py" --cwd "%SCRIPT_ROOT%" --stdout "%TEMP%\nulla_gateway.log" --stderr "%TEMP%\nulla_gateway.err.log" -- "!OPENCLAW_CMD!" gateway run --force --port 18789 >nul
-    echo   Starting the OpenClaw gateway (usually a few seconds)...
+    echo   Starting the OpenClaw gateway ^(usually a few seconds^)...
     for /L %%j in (1,1,90) do (
       powershell -NoProfile -Command "Start-Sleep -Seconds 1" >nul 2>&1
       powershell -NoProfile -Command "if (Test-NetConnection -ComputerName 127.0.0.1 -Port 18789 -InformationLevel Quiet -WarningAction SilentlyContinue) { exit 0 } else { exit 1 }" >nul 2>&1