feat: 인쇄에 투약주기/병용약 추가 + 인쇄 피드백 개선

- 인쇄 API: component_guide JOIN 추가
- 영수증에 ★ 투약 주기 ★ / ★ 함께 투약 권장 ★ 섹션 추가
- 인쇄 버튼: 로딩 중 → 인쇄 완료! 피드백
- 이모지 대신 ★ 사용 (프린터 호환)

backend/app.py

@@ -6446,17 +6446,24 @@ def api_animal_drug_info_print():
             with pg_engine.connect() as conn:
                 result = conn.execute(text("""
                     SELECT 
-                        product_name,
-                        company_name,
-                        main_ingredient,
-                        efficacy_effect,
-                        dosage_instructions,
-                        precautions,
-                        weight_min_kg,
-                        weight_max_kg,
-                        pet_size_label
-                    FROM apc 
-                    WHERE apc = :apc
+                        a.product_name,
+                        a.company_name,
+                        a.main_ingredient,
+                        a.efficacy_effect,
+                        a.dosage_instructions,
+                        a.precautions,
+                        a.weight_min_kg,
+                        a.weight_max_kg,
+                        a.pet_size_label,
+                        a.component_code,
+                        g.component_name_ko,
+                        g.dosing_interval_adult,
+                        g.dosing_interval_high_risk,
+                        g.dosing_interval_puppy,
+                        g.companion_drugs
+                    FROM apc a
+                    LEFT JOIN component_guide g ON a.component_code = g.component_code
+                    WHERE a.apc = :apc
                     LIMIT 1
                 """), {'apc': apc})
                 row = result.fetchone()
@@ -6591,6 +6598,27 @@ def api_animal_drug_info_print():
                 for line in wrap_text(para.strip(), 44):
                     message += f"  {line}\n"
         
+        # 투약 주기 (component_guide JOIN)
+        if row.dosing_interval_adult:
+            message += f"""
+{THIN}
+★ 투약 주기 ★
+"""
+            message += f"  일반: {row.dosing_interval_adult}\n"
+            if row.dosing_interval_high_risk:
+                message += f"  고위험: {row.dosing_interval_high_risk}\n"
+            if row.dosing_interval_puppy:
+                message += f"  새끼: {row.dosing_interval_puppy}\n"
+        
+        # 병용약 권장 (component_guide JOIN)
+        if row.companion_drugs:
+            message += f"""
+{THIN}
+★ 함께 투약 권장 ★
+"""
+            for line in wrap_text(row.companion_drugs, 44):
+                message += f"  {line}\n"
+        
         message += f"""
 {LINE}
                     청 춘 약 국