fix: Replace PAUSE with message syntax (not supported in DOS 6.22)

Issue: DOS 6.22 PAUSE command does not accept message text as parameter.
The syntax "PAUSE message..." is a Windows NT/2000+ feature that causes
command-line parameters (%1, %2, etc.) to be consumed/lost in DOS 6.22.

Root cause: User ran "T:\DEPLOY.BAT TS-4R" but script reported
"Machine name not provided". The parameter %1 was being consumed by
the invalid PAUSE syntax at line 31 before reaching GET_MACHINE_NAME.

Changes:
- Fixed 46 PAUSE commands across 9 BAT files
- Converted "PAUSE message..." to "ECHO message..." + "PAUSE"
- Updated check-dos-compatibility.ps1 to detect PAUSE with message
- Created fix-pause-syntax.ps1 automated fix script

Example fix:
BEFORE (Windows NT+ syntax, causes parameter loss):
  PAUSE Press any key to continue...

AFTER (DOS 6.22 compatible):
  ECHO Press any key to continue...
  PAUSE

DOS 6.22 PAUSE command:
- Syntax: PAUSE (no parameters)
- Displays: "Press any key to continue..."
- Cannot customize message (built-in text only)

Files modified:
- DEPLOY.BAT: 10 PAUSE commands fixed
- UPDATE.BAT: 7 PAUSE commands fixed
- CTONW.BAT: 8 PAUSE commands fixed
- NWTOC.BAT: 6 PAUSE commands fixed
- REBOOT.BAT: 4 PAUSE commands fixed
- STAGE.BAT: 6 PAUSE commands fixed
- CHECKUPD.BAT: 2 PAUSE commands fixed
- DOSTEST.BAT: 2 PAUSE commands fixed
- AUTOEXEC.BAT: 1 PAUSE command fixed

Deployed to:
- D2TESTNAS: /data/test/*.BAT (9,908 bytes for DEPLOY.BAT)

Testing: Should now correctly receive command-line parameter:
  T:\DEPLOY.BAT TS-4R

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

UPDATE.BAT

@@ -26,7 +26,8 @@ ECHO.
 ECHO Or set MACHINE variable in AUTOEXEC.BAT:
 ECHO   SET MACHINE=TS-4R
 ECHO.
-PAUSE Press any key to exit...
+ECHO Press any key to exit...
+PAUSE
 GOTO END
 
 :USE_PARAM
@@ -74,7 +75,8 @@ ECHO.
 ECHO Or map manually:
 ECHO   NET USE T: \\D2TESTNAS\test /YES
 ECHO.
-PAUSE Press any key to exit...
+ECHO Press any key to exit...
+PAUSE
 GOTO END
 
 REM ==================================================================
@@ -154,7 +156,8 @@ ECHO - T: drive is writable
 ECHO - Sufficient disk space on T:
 ECHO - Network connection is stable
 ECHO.
-PAUSE Press any key to exit...
+ECHO Press any key to exit...
+PAUSE
 GOTO END
 
 :DISK_ERROR
@@ -166,7 +169,8 @@ ECHO - Target drive is full
 ECHO - Network connection lost
 ECHO - Permission denied
 ECHO.
-PAUSE Press any key to exit...
+ECHO Press any key to exit...
+PAUSE
 GOTO END
 
 :INIT_ERROR
@@ -178,7 +182,8 @@ ECHO - Insufficient memory
 ECHO - Invalid path
 ECHO - Target drive not accessible
 ECHO.
-PAUSE Press any key to exit...
+ECHO Press any key to exit...
+PAUSE
 GOTO END
 
 :USER_ABORT
@@ -187,7 +192,8 @@ ECHO [WARNING] Backup terminated by user (Ctrl+C)
 ECHO.
 ECHO Backup may be incomplete!
 ECHO.
-PAUSE Press any key to exit...
+ECHO Press any key to exit...
+PAUSE
 GOTO END
 
 :NO_FILES
@@ -198,7 +204,8 @@ ECHO This may indicate:
 ECHO - All files are already up to date (/D option)
 ECHO - Source drive is empty
 ECHO.
-PAUSE Press any key to exit...
+ECHO Press any key to exit...
+PAUSE
 GOTO END
 
 REM ==================================================================