feat: 영수증 인쇄를 TCP→DLL 방식으로 전환

TCP 소켓(PRINTSTART/PRINTEND) 대신 AllThatPayCatReqMC(iCmd=2)로
DLL→MMF 경유 인쇄. GW 포트 변경에 영향받지 않음.

- ProcessPrint: TCP 소켓 제거, DLL CatReqMC(2) 호출로 대체
- FindGWPort: 8080/7779 포트 제외 로직 추가
- 실패 시 FindGWPort+ConnectDLL 재연결 후 1회 재시도
- build.bat, test_print_dll.ps1 추가 (DLL 인쇄 단독 테스트용)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

test_print_dll.ps1

@@ -0,0 +1,105 @@
+# 32비트 PowerShell에서 AllthatModule.dll iCmd=2 영수증출력 테스트
+# 실행: C:\Windows\SysWOW64\WindowsPowerShell\v1.0\powershell.exe -ExecutionPolicy Bypass -File test_print_dll.ps1
+
+Add-Type -TypeDefinition @"
+using System;
+using System.Runtime.InteropServices;
+
+public class AllThatPay {
+    private const string DLL = @"C:\Program Files (x86)\AllthatpayClient\AllthatModule.dll";
+
+    [DllImport(DLL, CharSet = CharSet.Ansi, CallingConvention = CallingConvention.StdCall)]
+    public static extern int AllThatPayOpenModule(string gwIp, string gwPort, string atpIp, string atpPort, string bizNo, string ediType, int optFlag);
+
+    [DllImport(DLL, CharSet = CharSet.Ansi, CallingConvention = CallingConvention.StdCall)]
+    public static extern int AllThatPayCloseModule();
+
+    [DllImport(DLL, CallingConvention = CallingConvention.StdCall)]
+    public static extern int AllThatPayCatReqMC(int iCmd, byte[] pInBuf, int iInLength);
+
+    [DllImport(DLL, CallingConvention = CallingConvention.StdCall)]
+    public static extern int AllThatPayRetCon();
+
+    [DllImport(DLL, CallingConvention = CallingConvention.StdCall)]
+    public static extern IntPtr AllThatPayRetData(int iPosition);
+}
+"@
+
+# --- GW 포트 자동 탐지 ---
+$gwPort = $null
+$proc = Get-Process -Name "AllthatpayClient" -ErrorAction SilentlyContinue | Select-Object -First 1
+if ($proc) {
+    $netstat = netstat -ano 2>$null
+    foreach ($line in $netstat) {
+        if ($line -match "LISTENING" -and $line -match "\s$($proc.Id)\s*$") {
+            if ($line -match ":(\d+)\s") {
+                $port = [int]$Matches[1]
+                if ($port -ne 8080 -and $port -ne 7779) {
+                    $gwPort = $port.ToString()
+                    break
+                }
+            }
+        }
+    }
+}
+
+if (-not $gwPort) {
+    Write-Host "[ERROR] GW port not found" -ForegroundColor Red
+    exit 1
+}
+Write-Host "[INFO] GW Port: $gwPort" -ForegroundColor Cyan
+
+# --- DLL 연결 ---
+$r = [AllThatPay]::AllThatPayOpenModule("127.0.0.1", $gwPort, "", "", "8134500294", "P01", 0)
+Write-Host "[INFO] OpenModule: $r (1=OK)" -ForegroundColor $(if ($r -eq 1) {"Green"} else {"Red"})
+
+if ($r -ne 1) {
+    Write-Host "[ERROR] OpenModule failed" -ForegroundColor Red
+    exit 1
+}
+
+# --- 영수증 텍스트 (EUC-KR) ---
+$eucKr = [System.Text.Encoding]::GetEncoding("euc-kr")
+
+$text = "================================================`n"
+$text += "            [ 청 춘 약 국 ]`n"
+$text += "     경기 양주시 양주역로 7-3 1층`n"
+$text += "          TEL: 033-481-7390`n"
+$text += "================================================`n"
+$text += "`n"
+$text += "  ** DLL iCmd=2 인쇄 테스트 **`n"
+$text += "  시간: $(Get-Date -Format 'yyyy-MM-dd HH:mm:ss')`n"
+$text += "`n"
+$text += "------------------------------------------------`n"
+$text += "          ★ 마일리지 적립 ★`n"
+$text += "   QR 스캔하고 100P 받으세요!`n"
+$text += "         (유효기간: 30일)`n"
+$text += "------------------------------------------------`n"
+$text += "`n`n"
+
+$textBytes = $eucKr.GetBytes($text)
+
+# --- QR 코드 추가: FS×4 + ATQR_URL (명세서 CMD 2 규격) ---
+$qrUrl = "https://shc.pharmq.kr/claim?t=test_dll_print"
+[byte]$fs = 0x1C
+$qrTag = $eucKr.GetBytes("ATQR_" + $qrUrl)
+
+$buf = New-Object System.Collections.Generic.List[byte]
+$buf.AddRange($textBytes)
+$buf.Add($fs); $buf.Add($fs); $buf.Add($fs); $buf.Add($fs)
+$buf.AddRange($qrTag)
+$packet = $buf.ToArray()
+
+Write-Host "[INFO] iCmd=2 send ($($packet.Length) bytes, text=$($textBytes.Length) + QR=$($qrTag.Length))..." -ForegroundColor Yellow
+
+# --- iCmd=2 영수증출력 ---
+try {
+    $pr = [AllThatPay]::AllThatPayCatReqMC(2, $packet, $packet.Length)
+    Write-Host "[INFO] CatReqMC(2): $pr" -ForegroundColor $(if ($pr -ne 0) {"Green"} else {"Red"})
+} catch {
+    Write-Host "[ERROR] CatReqMC exception: $_" -ForegroundColor Red
+}
+
+# --- 정리 ---
+try { [AllThatPay]::AllThatPayCloseModule() | Out-Null } catch {}
+Write-Host "[DONE]" -ForegroundColor Cyan