feat: 도매상 설정 중앙 관리 시스템

- config/wholesalers.json: 도매상 정보 중앙 관리 (ID, 이름, 로고, 색상, API)
- config/__init__.py: Python 헬퍼 (get_wholesalers, get_wholesaler)
- wholesaler_config_api.py: /api/config/wholesalers 엔드포인트
- 백제약품 로고(favicon) 추가: logo_baekje.ico
- 잔고 모달에 로고 표시 기능 추가

backend/templates/admin_rx_usage.html

@@ -2210,6 +2210,20 @@
     .balance-icon.geoyoung { background: linear-gradient(135deg, #0891b2, #06b6d4); }
     .balance-icon.sooin { background: linear-gradient(135deg, #7c3aed, #a855f7); }
     
+    .balance-logo-wrap {
+        width: 48px;
+        height: 48px;
+        display: flex;
+        align-items: center;
+        justify-content: center;
+    }
+    .balance-logo {
+        width: 40px;
+        height: 40px;
+        object-fit: contain;
+        border-radius: 8px;
+    }
+    
     .balance-info {
         flex: 1;
         min-width: 0;
@@ -2281,6 +2295,26 @@
         document.getElementById('balanceModal').classList.remove('show');
     }
     
+    // 도매상 설정 (중앙 관리)
+    const WHOLESALER_CONFIG = {
+        baekje: { 
+            id: 'baekje', name: '백제약품', icon: '💉', 
+            logo: '/static/img/logo_baekje.ico',
+            color: '#f59e0b', api: '/api/baekje/balance' 
+        },
+        geoyoung: { 
+            id: 'geoyoung', name: '지오영', icon: '🏭', 
+            logo: '/static/img/logo_geoyoung.ico',
+            color: '#06b6d4', api: '/api/geoyoung/balance' 
+        },
+        sooin: { 
+            id: 'sooin', name: '수인약품', icon: '💊', 
+            logo: '/static/img/logo_sooin.svg',
+            color: '#a855f7', api: '/api/sooin/balance' 
+        }
+    };
+    const WHOLESALER_ORDER = ['baekje', 'geoyoung', 'sooin'];
+    
     async function loadBalances() {
         const content = document.getElementById('balanceContent');
         content.innerHTML = `
@@ -2289,11 +2323,7 @@
                 <div>잔고 조회 중...</div>
             </div>`;
         
-        const wholesalers = [
-            { id: 'baekje', name: '백제약품', icon: '💉', api: '/api/baekje/balance' },
-            { id: 'geoyoung', name: '지오영', icon: '🏭', api: '/api/geoyoung/balance' },
-            { id: 'sooin', name: '수인약품', icon: '💊', api: '/api/sooin/balance' }
-        ];
+        const wholesalers = WHOLESALER_ORDER.map(id => WHOLESALER_CONFIG[id]);
         
         const results = {};
         let totalBalance = 0;
@@ -2323,7 +2353,11 @@
             
             html += `
                 <div class="balance-card ${isError ? 'error' : ''}">
-                    <div class="balance-icon ${ws.id}">${ws.icon}</div>
+                    <div class="balance-logo-wrap">
+                        <img src="${ws.logo}" alt="${ws.name}" class="balance-logo" 
+                             onerror="this.style.display='none'; this.nextElementSibling.style.display='flex';">
+                        <div class="balance-icon ${ws.id}" style="display:none;">${ws.icon}</div>
+                    </div>
                     <div class="balance-info">
                         <div class="balance-name">${ws.name}</div>
                         <div class="balance-detail">