fix: Remove multi-line IF blocks with parentheses from batch files

Issue: DOS 6.22 does not support multi-line IF ( ... ) blocks or
ELSE clauses, causing "Bad command or file name" errors in DEPLOY.BAT
Step 5 (Updating AUTOEXEC.BAT).

Root cause: Parentheses for multi-line IF blocks were added in later
DOS versions. DOS 6.22 only supports single-line IF statements.

Changes:
- Converted IF ( ... ) ELSE ( ... ) to GOTO label structure
- Converted IF ( nested commands ) to GOTO label structure
- Updated check-dos-compatibility.ps1 to detect IF ( ... ) syntax
- Created fix-if-blocks.ps1 automated fix script

Example fix:
BEFORE (DOS error):
  IF EXIST file (
      command1
      command2
  ) ELSE (
      command3
  )

AFTER (DOS 6.22 compatible):
  IF NOT EXIST file GOTO ELSE_LABEL
  command1
  command2
  GOTO END_LABEL
  :ELSE_LABEL
  command3
  :END_LABEL

Files modified:
- DEPLOY.BAT: Fixed 2 multi-line IF blocks (lines 164, 244)
- Added labels: NO_AUTOEXEC_BACKUP, AUTOEXEC_BACKUP_DONE, ADD_MACHINE_VAR

DOS 6.22 IF syntax:
- Single-line only: IF condition command
- No parentheses: IF condition ( ... )
- No ELSE clause: ) ELSE (
- Use GOTO for multi-step logic

Deployed to:
- D2TESTNAS: /data/test/DEPLOY.BAT (9,848 bytes)

Testing: Should resolve "Bad command or file name" error at Step 5

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

DEPLOY_TEST.BAT

@@ -161,14 +161,18 @@ ECHO [STEP 4/5] Installing update system files...
 ECHO.
 
 REM Backup current AUTOEXEC.BAT
-IF EXIST C:\AUTOEXEC.BAT (
-    ECHO Backing up AUTOEXEC.BAT...
-    COPY C:\AUTOEXEC.BAT C:\AUTOEXEC.SAV >NUL
-    IF ERRORLEVEL 1 GOTO BACKUP_ERROR
-    ECHO [OK] Backup created: C:\AUTOEXEC.SAV
-) ELSE (
-    ECHO [WARNING] No existing AUTOEXEC.BAT found
-)
+IF NOT EXIST C:\AUTOEXEC.BAT GOTO NO_AUTOEXEC_BACKUP
+
+ECHO Backing up AUTOEXEC.BAT...
+COPY C:\AUTOEXEC.BAT C:\AUTOEXEC.SAV >NUL
+IF ERRORLEVEL 1 GOTO BACKUP_ERROR
+ECHO [OK] Backup created: C:\AUTOEXEC.SAV
+GOTO AUTOEXEC_BACKUP_DONE
+
+:NO_AUTOEXEC_BACKUP
+ECHO [WARNING] No existing AUTOEXEC.BAT found
+
+:AUTOEXEC_BACKUP_DONE
 ECHO.
 
 REM Create C:\BAT directory if it doesn't exist
@@ -241,10 +245,12 @@ ECHO [STEP 5/5] Updating AUTOEXEC.BAT...
 ECHO.
 
 REM Check if MACHINE variable already exists in AUTOEXEC.BAT
-IF EXIST C:\AUTOEXEC.BAT (
-    FIND "SET MACHINE=" C:\AUTOEXEC.BAT >NUL
-    IF NOT ERRORLEVEL 1 GOTO MACHINE_EXISTS
-)
+IF NOT EXIST C:\AUTOEXEC.BAT GOTO ADD_MACHINE_VAR
+
+FIND "SET MACHINE=" C:\AUTOEXEC.BAT >NUL
+IF NOT ERRORLEVEL 1 GOTO MACHINE_EXISTS
+
+:ADD_MACHINE_VAR
 
 REM Append MACHINE variable to AUTOEXEC.BAT
 ECHO SET MACHINE=%MACHINE% >> C:\AUTOEXEC.BAT