feat: PAAI 자동인쇄 기능 완성 (EUC-KR 텍스트 방식)

추가:
- 자동인쇄 ON/OFF 토글 (헤더)
- ESC/POS 영수증 인쇄 (EUC-KR 인코딩)
- ESCPOS_TROUBLESHOOTING.md 트러블슈팅 문서

핵심 변경:
- 이미지 방식 -> 텍스트 방식 (socket 직접 전송)
- UTF-8 -> EUC-KR 인코딩
- 이모지 제거 ([V], [!], >> 사용)
- 48자 기준 줄바꿈

인쇄 흐름:
1. PAAI 분석 완료
2. 자동인쇄 ON이면 /pmr/api/paai/print 호출
3. _format_paai_receipt()로 텍스트 생성
4. _print_escpos_text()로 프린터 전송

참고: docs/ESCPOS_TROUBLESHOOTING.md

backend/paai_printer.py

@@ -0,0 +1,159 @@
+"""PAAI ESC/POS 프린터 모듈"""
+import json
+from datetime import datetime
+from escpos.printer import Network
+from PIL import Image, ImageDraw, ImageFont
+
+# 프린터 설정
+PRINTER_IP = "192.168.0.174"
+PRINTER_PORT = 9100
+THERMAL_WIDTH = 576
+
+
+def print_paai_result(pre_serial: str, patient_name: str, analysis: dict, kims_summary: dict) -> dict:
+    """PAAI 분석 결과 인쇄"""
+    try:
+        # 이미지 생성
+        img = create_receipt_image(pre_serial, patient_name, analysis, kims_summary)
+        
+        # 프린터 연결 및 출력
+        p = Network(PRINTER_IP, port=PRINTER_PORT, timeout=15)
+        p.image(img)
+        p.text('\n\n\n')
+        p.cut()
+        
+        return {'success': True, 'message': '인쇄 완료'}
+    except Exception as e:
+        return {'success': False, 'error': str(e)}
+
+
+def create_receipt_image(pre_serial: str, patient_name: str, analysis: dict, kims_summary: dict) -> Image:
+    """영수증 이미지 생성"""
+    # 폰트
+    try:
+        font_title = ImageFont.truetype('malgun.ttf', 28)
+        font_section = ImageFont.truetype('malgunbd.ttf', 20)
+        font_normal = ImageFont.truetype('malgun.ttf', 18)
+        font_small = ImageFont.truetype('malgun.ttf', 15)
+    except:
+        font_title = ImageFont.load_default()
+        font_section = font_title
+        font_normal = font_title
+        font_small = font_title
+    
+    width = THERMAL_WIDTH
+    padding = 20
+    y = padding
+    
+    # 이미지 생성
+    img = Image.new('RGB', (width, 1000), 'white')
+    draw = ImageDraw.Draw(img)
+    
+    # 헤더
+    draw.text((width//2, y), 'PAAI 복약안내', font=font_title, fill='black', anchor='mt')
+    y += 40
+    draw.line([(padding, y), (width-padding, y)], fill='black', width=1)
+    y += 15
+    
+    # 환자 정보
+    draw.text((padding, y), f'환자: {patient_name}', font=font_normal, fill='black')
+    y += 25
+    draw.text((padding, y), f'처방번호: {pre_serial}', font=font_small, fill='black')
+    y += 20
+    now_str = datetime.now().strftime("%Y-%m-%d %H:%M")
+    draw.text((padding, y), f'출력: {now_str}', font=font_small, fill='black')
+    y += 25
+    draw.line([(padding, y), (width-padding, y)], fill='black', width=1)
+    y += 15
+    
+    # 상호작용
+    interaction_count = kims_summary.get('interaction_count', 0)
+    has_severe = kims_summary.get('has_severe', False)
+    
+    if has_severe:
+        draw.text((padding, y), '[주의] 중증 상호작용 있음!', font=font_section, fill='black')
+    elif interaction_count > 0:
+        draw.text((padding, y), f'약물 상호작용: {interaction_count}건', font=font_normal, fill='black')
+    else:
+        draw.text((padding, y), '상호작용 없음', font=font_normal, fill='black')
+    y += 30
+    
+    # 처방 해석
+    insight = analysis.get('prescription_insight', '')
+    if insight:
+        draw.text((padding, y), '[처방 해석]', font=font_section, fill='black')
+        y += 28
+        for line in wrap_text(insight, 40)[:3]:
+            draw.text((padding, y), line, font=font_small, fill='black')
+            y += 20
+        y += 10
+    
+    # 주의사항
+    cautions = analysis.get('cautions', [])
+    if cautions:
+        draw.text((padding, y), '[복용 주의사항]', font=font_section, fill='black')
+        y += 28
+        for i, c in enumerate(cautions[:3], 1):
+            for line in wrap_text(f'{i}. {c}', 40)[:2]:
+                draw.text((padding, y), line, font=font_small, fill='black')
+                y += 20
+        y += 10
+    
+    # 상담 포인트
+    counseling = analysis.get('counseling_points', [])
+    if counseling:
+        draw.text((padding, y), '[상담 포인트]', font=font_section, fill='black')
+        y += 28
+        for i, c in enumerate(counseling[:2], 1):
+            for line in wrap_text(f'{i}. {c}', 40)[:2]:
+                draw.text((padding, y), line, font=font_small, fill='black')
+                y += 20
+        y += 10
+    
+    # 푸터
+    y += 10
+    draw.line([(padding, y), (width-padding, y)], fill='black', width=1)
+    y += 15
+    draw.text((width//2, y), '양구청춘약국 PAAI', font=font_small, fill='black', anchor='mt')
+    
+    return img.crop((0, 0, width, y + 30))
+
+
+def wrap_text(text: str, max_chars: int = 40) -> list:
+    """텍스트 줄바꿈"""
+    lines = []
+    words = text.split()
+    current = ""
+    
+    for word in words:
+        if len(current) + len(word) + 1 <= max_chars:
+            current = current + " " + word if current else word
+        else:
+            if current:
+                lines.append(current)
+            current = word
+    
+    if current:
+        lines.append(current)
+    
+    return lines if lines else [text[:max_chars]]
+
+
+if __name__ == '__main__':
+    # CLI 테스트
+    import sys
+    if len(sys.argv) > 1:
+        pre_serial = sys.argv[1]
+    else:
+        pre_serial = '20260305000075'
+    
+    # 테스트 데이터
+    analysis = {
+        'prescription_insight': '테스트 처방입니다.',
+        'cautions': ['주의사항 1', '주의사항 2'],
+        'counseling_points': ['상담 포인트 1']
+    }
+    kims_summary = {'interaction_count': 0, 'has_severe': False}
+    
+    result = print_paai_result(pre_serial, '테스트환자', analysis, kims_summary)
+    print(result)