fix(prediction): 시뮬레이션 API를 localhost 대신 api 인스턴스 사용

fetch('http://localhost:3001/...') → api.post('/simulation/run', ...)
배포 환경에서 CORS loopback 차단 문제 해결

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/tabs/prediction/components/OilSpillView.tsx

@@ -14,6 +14,7 @@ import type { BacktrackPhase, BacktrackVessel, BacktrackConditions, ReplayShip,
 import { TOTAL_REPLAY_FRAMES } from '@common/types/backtrack'
 import { fetchBacktrackByAcdnt, createBacktrack, fetchPredictionDetail } from '../services/predictionApi'
 import type { PredictionDetail } from '../services/predictionApi'
+import { api } from '@common/services/api'
 
 export type PredictionModel = 'KOSPS' | 'POSEIDON' | 'OpenDrift'
 // eslint-disable-next-line react-refresh/only-export-components
@@ -259,27 +260,16 @@ export function OilSpillView() {
       const models = Array.from(selectedModels)
       const results = await Promise.all(
         models.map(async (model) => {
-          const response = await fetch('http://localhost:3001/api/simulation/run', {
-            method: 'POST',
-            headers: { 'Content-Type': 'application/json' },
-            body: JSON.stringify({
-              model,
-              lat: incidentCoord.lat,
-              lon: incidentCoord.lon,
-              duration_hours: predictionTime,
-              oil_type: oilType,
-              spill_amount: spillAmount,
-              spill_type: spillType
-            })
+          const { data } = await api.post<{ trajectory: Array<{ lat: number; lon: number; time: number; particle?: number }> }>('/simulation/run', {
+            model,
+            lat: incidentCoord.lat,
+            lon: incidentCoord.lon,
+            duration_hours: predictionTime,
+            oil_type: oilType,
+            spill_amount: spillAmount,
+            spill_type: spillType,
           })
-
-          if (!response.ok) {
-            throw new Error(`API 오류 (${model}): ${response.status}`)
-          }
-
-          const data = await response.json()
-          return (data.trajectory as Array<{ lat: number; lon: number; time: number; particle?: number }>)
-            .map(p => ({ ...p, model }))
+          return data.trajectory.map(p => ({ ...p, model }))
         })
       )