feat(재고): 약품 더블클릭 시 입고이력 모달 추가

- 새 API: GET /api/drugs/<drug_code>/purchase-history
  - WH_sub + WH_main + PM_BASE.CD_custom 조인
  - 도매상명, 입고일, 수량, 단가, 전화번호 반환
- admin_products.html 업데이트:
  - tr ondblclick → openPurchaseModal()
  - 입고이력 모달 UI/스타일 추가
  - 도매상 전화번호 클릭 시 복사 기능
  - 결과 카운트 옆에 더블클릭 힌트 추가
- 기타 onclick에 event.stopPropagation() 추가 (충돌 방지)

backend/app.py

@@ -3639,6 +3639,69 @@ def api_products():
         return jsonify({'success': False, 'error': str(e)}), 500
 
 
+# ==================== 입고이력 API ====================
+
+@app.route('/api/drugs/<drug_code>/purchase-history')
+def api_drug_purchase_history(drug_code):
+    """
+    약품 입고이력 조회 API
+    - WH_sub: 입고 상세 (약품코드, 수량, 단가)
+    - WH_main: 입고 마스터 (입고일, 도매상코드)
+    - PM_BASE.CD_custom: 도매상명
+    """
+    try:
+        drug_session = db_manager.get_session('PM_DRUG')
+        
+        # 입고이력 조회 (최근 100건)
+        result = drug_session.execute(text("""
+            SELECT TOP 100
+                m.WH_DT_appl as purchase_date,
+                COALESCE(c.CD_NM_custom, m.WH_BUSINAME, '미확인') as supplier_name,
+                CAST(COALESCE(s.WH_NM_item_a, 0) AS INT) as quantity,
+                CAST(COALESCE(s.WH_MY_unit_a, 0) AS INT) as unit_price,
+                c.CD_TEL_charge1 as supplier_tel
+            FROM WH_sub s
+            JOIN WH_main m ON m.WH_NO_stock = s.WH_SR_stock AND m.WH_DT_appl = s.WH_DT_appl
+            LEFT JOIN PM_BASE.dbo.CD_custom c ON m.WH_CD_cust_sale = c.CD_CD_custom
+            WHERE s.DrugCode = :drug_code
+            ORDER BY m.WH_DT_appl DESC
+        """), {'drug_code': drug_code})
+        
+        history = []
+        for row in result.fetchall():
+            # 날짜 포맷팅 (YYYYMMDD -> YYYY-MM-DD)
+            date_str = row.purchase_date or ''
+            if len(date_str) == 8:
+                date_str = f"{date_str[:4]}-{date_str[4:6]}-{date_str[6:8]}"
+            
+            history.append({
+                'date': date_str,
+                'supplier': row.supplier_name or '미확인',
+                'quantity': row.quantity or 0,
+                'unit_price': row.unit_price or 0,
+                'supplier_tel': row.supplier_tel or ''
+            })
+        
+        # 약품명 조회
+        name_result = drug_session.execute(text("""
+            SELECT GoodsName FROM CD_GOODS WHERE DrugCode = :drug_code
+        """), {'drug_code': drug_code})
+        name_row = name_result.fetchone()
+        drug_name = name_row[0] if name_row else drug_code
+        
+        return jsonify({
+            'success': True,
+            'drug_code': drug_code,
+            'drug_name': drug_name,
+            'history': history,
+            'count': len(history)
+        })
+        
+    except Exception as e:
+        logging.error(f"입고이력 조회 오류: {e}")
+        return jsonify({'success': False, 'error': str(e)}), 500
+
+
 # ==================== 위치 정보 API ====================
 
 @app.route('/api/locations')
@@ -5245,7 +5308,9 @@ def admin_return_management():
 
 @app.route('/api/return-candidates')
 def api_return_candidates():
-    """반품 후보 목록 조회 API"""
+    """반품 후보 목록 조회 API (가격 정보 포함)"""
+    import pyodbc
+    
     status = request.args.get('status', '')
     urgency = request.args.get('urgency', '')
     search = request.args.get('search', '')
@@ -5292,13 +5357,81 @@ def api_return_candidates():
         cursor.execute(query, params)
         rows = cursor.fetchall()
         
+        # 약품코드 목록 추출
+        drug_codes = [row['drug_code'] for row in rows]
+        
+        # MSSQL에서 가격 정보 조회 (한 번에)
+        price_map = {}
+        if drug_codes:
+            try:
+                mssql_conn_str = (
+                    'DRIVER={ODBC Driver 17 for SQL Server};'
+                    'SERVER=192.168.0.4\\PM2014;'
+                    'DATABASE=PM_DRUG;'
+                    'UID=sa;'
+                    'PWD=tmddls214!%(;'
+                    'TrustServerCertificate=yes;'
+                    'Connection Timeout=5'
+                )
+                mssql_conn = pyodbc.connect(mssql_conn_str, timeout=5)
+                mssql_cursor = mssql_conn.cursor()
+                
+                # IN 절 생성 (SQL Injection 방지를 위해 파라미터화)
+                # Price가 없으면 Saleprice, Topprice 순으로 fallback
+                placeholders = ','.join(['?' for _ in drug_codes])
+                mssql_cursor.execute(f"""
+                    SELECT DrugCode, 
+                           COALESCE(NULLIF(Price, 0), NULLIF(Saleprice, 0), NULLIF(Topprice, 0), 0) as BestPrice
+                    FROM CD_GOODS 
+                    WHERE DrugCode IN ({placeholders})
+                """, drug_codes)
+                
+                for row in mssql_cursor.fetchall():
+                    price_map[row[0]] = float(row[1]) if row[1] else 0
+                
+                mssql_conn.close()
+            except Exception as e:
+                logging.warning(f"MSSQL 가격 조회 실패: {e}")
+        
+        # 전체 데이터 조회 (통계용)
+        cursor.execute("SELECT drug_code, current_stock, months_since_use, months_since_purchase FROM return_candidates")
+        all_rows = cursor.fetchall()
+        
+        # 긴급도별 금액 합계 계산
+        total_amount = 0
+        critical_amount = 0
+        warning_amount = 0
+        
+        for row in all_rows:
+            code = row['drug_code']
+            stock = row['current_stock'] or 0
+            price = price_map.get(code, 0)
+            amount = stock * price
+            
+            months_use = row['months_since_use'] or 0
+            months_purchase = row['months_since_purchase'] or 0
+            max_months = max(months_use, months_purchase)
+            
+            total_amount += amount
+            if max_months >= 36:
+                critical_amount += amount
+            elif max_months >= 24:
+                warning_amount += amount
+        
         items = []
         for row in rows:
+            code = row['drug_code']
+            stock = row['current_stock'] or 0
+            price = price_map.get(code, 0)
+            recoverable = stock * price
+            
             items.append({
                 'id': row['id'],
-                'drug_code': row['drug_code'],
+                'drug_code': code,
                 'drug_name': row['drug_name'],
-                'current_stock': row['current_stock'],
+                'current_stock': stock,
+                'unit_price': price,
+                'recoverable_amount': recoverable,
                 'last_prescription_date': row['last_prescription_date'],
                 'months_since_use': row['months_since_use'],
                 'last_purchase_date': row['last_purchase_date'],
@@ -5337,7 +5470,10 @@ def api_return_candidates():
                 'warning': warning,
                 'pending': pending,
                 'processed': processed,
-                'total': total
+                'total': total,
+                'total_amount': total_amount,
+                'critical_amount': critical_amount,
+                'warning_amount': warning_amount
             }
         })