fix(web): Y按鈕簽核回應解析錯誤 - result.status → result.approval.status

根因: API 回傳 {approval: {status: 'approved'}} 但前端誤檢查 result.status

修復:
- dual-state-incident-card.tsx: 正確解析 result.approval.status
- api-client.ts: 更新回傳型別與後端對齊

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

apps/web/src/components/incident/dual-state-incident-card.tsx

@@ -141,13 +141,17 @@ export const DualStateIncidentCard: React.FC<DualStateIncidentCardProps> = ({
         timeoutRef.current = null
       }
 
-      if (result.status === 'approved' || result.status === 'APPROVED') {
+      // 🔧 Fix: 正確檢查 result.approval.status (非 result.status)
+      const approvalStatus = result.approval?.status?.toLowerCase()
+      if (approvalStatus === 'approved') {
         setButtonState('approved')
         console.log('🎯 授權成功，觸發 onApprovalChange')
         onApprovalChange?.(approvalId, 'approved')
       } else {
         // Multi-sig: 還需要更多簽核
-        console.log('🔐 Multi-sig 等待中，目前簽核:', result.current_signatures, '/', result.required_signatures)
+        const current = result.approval?.current_signatures ?? result.current_signatures ?? 0
+        const required = result.approval?.required_signatures ?? result.required_signatures ?? 1
+        console.log('🔐 Multi-sig 等待中，目前簽核:', current, '/', required)
         setButtonState('idle')
       }
     } catch (error) {