feat(account): 대출 실행금액 필드 추가 + 상환방식별 자동계산 분기

- loan_amount(대출 실행 금액) 컬럼 추가(DB/도메인/DTO/mapper)
- 계좌 폼: 대출 실행 금액 입력 / 기록 시작 시 잔액(기존 openingBalance) 레이블 분리
- 계좌 카드: 실행금액·금리·상환방식 표시
- 상환 자동계산 3방식 분기:
  - 원리금균등: 납입금액 입력 → 이자(잔액×월이율) / 원금(납입-이자) 분리
  - 원금균등: 실행금액÷기간=월원금, 잔액×월이율=이자 자동계산
  - 만기일시: 잔액×월이율=이자만 자동계산, 원금 0
- 자동계산 후 이자·원금 수동 조정 가능

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

src/views/account/AccountView.vue

@@ -127,6 +127,56 @@ const repayTargetIsCard = computed(() => {
   const w = wallets.value.find((x) => x.id === form.toWalletId)
   return !!w && w.type === 'CARD'
 })
+// 금리가 설정된 대출 계좌를 선택한 경우 자동계산 활성
+const repayTargetLoanWallet = computed(() => {
+  const w = wallets.value.find((x) => x.id === form.toWalletId)
+  return w?.type === 'LOAN' && w.loanRate ? w : null
+})
+// 납입금액 입력용 (원리금균등만 사용)
+const loanPaymentAmount = ref(null)
+
+function monthlyInterestOf(loan) {
+  return Math.round(Math.abs(loan.balance || 0) * (Number(loan.loanRate) / 100 / 12))
+}
+
+// 상환방식별 자동계산: 원금균등·만기일시는 납입금액 입력 불필요
+const loanAutoResult = computed(() => {
+  const loan = repayTargetLoanWallet.value
+  if (!loan) return null
+  const interest = monthlyInterestOf(loan)
+  if (loan.loanMethod === 'BULLET') {
+    return { interest, principal: 0, total: interest, needsInput: false }
+  }
+  if (loan.loanMethod === 'EQUAL_PRINCIPAL' && loan.loanAmount && loan.loanMonths) {
+    const principal = Math.round(Number(loan.loanAmount) / loan.loanMonths)
+    return { interest, principal, total: principal + interest, needsInput: false }
+  }
+  return { interest: null, principal: null, total: null, needsInput: true }
+})
+
+watch(loanAutoResult, (r) => {
+  if (r && !r.needsInput) {
+    form.interest = r.interest
+    form.principal = r.principal
+    loanPaymentAmount.value = r.total
+  }
+})
+
+function calcLoanRepayment(payment) {
+  const loan = repayTargetLoanWallet.value
+  if (!loan || !payment || payment <= 0) return
+  const interest = monthlyInterestOf(loan)
+  form.interest = Math.min(interest, payment)
+  form.principal = Math.max(0, payment - form.interest)
+}
+watch(loanPaymentAmount, (val) => {
+  if (loanAutoResult.value?.needsInput && val) calcLoanRepayment(Number(val))
+})
+watch(() => form.toWalletId, () => {
+  loanPaymentAmount.value = null
+  form.principal = null
+  form.interest = null
+})
 // 카드 지출일 때만 할부 입력 노출 (2~24개월, 일시불은 빈값)
 const showInstallment = computed(() => form.type === 'EXPENSE' && form.walletKind === 'CARD')
 const installmentMonthly = computed(() => {
@@ -293,11 +343,7 @@ const majorRows = computed(() => {
 const selectedMajorObj = computed(() =>
   majorOptionsData.value.find((m) => m.name === categoryMajor.value) ?? null
 )
-// 해당 행에 선택된 대분류가 포함되는지 확인
+
-function rowContainsSelected(row) {
-  if (!selectedMajorObj.value) return false
-  return row.some((m) => m.id === selectedMajorObj.value.id)
-}
 // 특정 대분류의 소분류 목록
 function subsByMajor(majorId) {
   return categories.value.filter((c) => c.parentId === majorId)
@@ -1139,8 +1185,34 @@ onMounted(async () => {
                     </option>
                   </select>
                 </label>
+                <!-- 금리 설정된 대출 계좌: 방식별 자동계산 -->
+                <template v-if="repayTargetLoanWallet">
+                  <!-- 원리금균등: 납입금액 직접 입력 -->
+                  <template v-if="loanAutoResult?.needsInput">
+                    <label>납입금액(원리금균등)
+                      <input v-model.number="loanPaymentAmount" type="number" min="0"
+                        placeholder="이번 달 납입할 총금액" :disabled="submitting" />
+                    </label>
+                  </template>
+                  <!-- 원금균등·만기일시: 자동계산 결과 표시 -->
+                  <template v-else>
+                    <div class="loan-breakdown">
+                      <span class="bd-label">{{ repayTargetLoanWallet.loanMethod === 'BULLET' ? '만기일시' : '원금균등' }} 자동계산</span>
+                      <span>납입 <b>{{ (loanAutoResult?.total || 0).toLocaleString('ko-KR') }}원</b></span>
+                    </div>
+                  </template>
+                  <!-- 계산 결과 표시 + 수동 조정 -->
+                  <div v-if="(form.interest ?? null) !== null || (form.principal ?? null) !== null" class="loan-breakdown">
+                    <span>이자 <b>{{ (form.interest || 0).toLocaleString('ko-KR') }}원</b></span>
+                    <span>원금 <b>{{ (form.principal || 0).toLocaleString('ko-KR') }}원</b></span>
+                  </div>
+                  <label>이자(조정)<input v-model.number="form.interest" type="number" min="0" :disabled="submitting" /></label>
+                  <label>원금(조정)<input v-model.number="form.principal" type="number" min="0" :disabled="submitting" /></label>
+                </template>
+                <template v-else>
                   <label>원금<input v-model.number="form.principal" type="number" min="0" placeholder="원 (이체로 기록)" :disabled="submitting" /></label>
                   <label>이자<input v-model.number="form.interest" type="number" min="0" placeholder="원 (지출·분류 이자)" :disabled="submitting" /></label>
+                </template>
                 <label v-if="repayTargetIsCard">연회비<input v-model.number="form.annualFee" type="number" min="0" placeholder="원 (지출·분류 연회비)" :disabled="submitting" /></label>
               </template>
 
@@ -1157,7 +1229,7 @@ onMounted(async () => {
                         @click="onMajorClick(m)"
                       >{{ m.name }}</button>
                     </div>
-                    <div v-if="rowContainsSelected(row) && selectedMajorObj && subsByMajor(selectedMajorObj.id).length" class="acc-sub-grid">
+                    <div v-if="selectedMajorObj && row.some(m => m.id === selectedMajorObj.id) && subsByMajor(selectedMajorObj.id).length" class="acc-sub-grid">
                       <button
                         v-for="s in subsByMajor(selectedMajorObj.id)" :key="s.id"
                         type="button" class="acc-chip sub"
@@ -1977,6 +2049,24 @@ button.primary {
 .acc-chip.add-chip.sub-add {
   flex: 0 0 auto;
 }
+.loan-breakdown {
+  display: flex;
+  gap: 1rem;
+  padding: 0.45rem 0.6rem;
+  border-radius: 6px;
+  background: var(--color-background-soft);
+  font-size: 0.85rem;
+  color: var(--color-text);
+}
+.loan-breakdown b {
+  color: hsla(160, 100%, 37%, 1);
+}
+.loan-breakdown .bd-label {
+  width: 100%;
+  font-size: 0.78rem;
+  opacity: 0.6;
+  margin-bottom: 0.1rem;
+}
 .tag-field {
   display: flex;
   flex-direction: column;

src/views/account/AccountWalletView.vue

@@ -33,6 +33,12 @@ const form = reactive({
   openingBalance: 0,
   openingDate: '',
   currentValue: null,
+  // 대출(LOAN) 전용
+  loanAmount: null,
+  loanRate: null,
+  loanMethod: '',
+  loanMonths: null,
+  loanStart: '',
 })
 const submitting = ref(false)
 const formError = ref(null)
@@ -196,7 +202,7 @@ function issuerLabel(t) {
   return t === 'BANK' ? '은행명' : t === 'CARD' ? '카드사' : t === 'INVEST' ? '증권사' : '대출기관'
 }
 function openingLabel(t) {
-  return t === 'BANK' || t === 'CASH' ? '초기 잔액' : t === 'CARD' ? '초기 미결제 금액' : t === 'INVEST' ? '투자금(투입원금)' : '대출 잔액(원금)'
+  return t === 'BANK' || t === 'CASH' ? '초기 잔액' : t === 'CARD' ? '초기 미결제 금액' : t === 'INVEST' ? '투자금(투입원금)' : '기록 시작 시 잔액'
 }
 // 투자 수익률(%) — 투입원금 대비 평가손익
 function returnPct(w) {
@@ -229,6 +235,11 @@ function openCreate() {
     openingBalance: 0,
     openingDate: '',
     currentValue: null,
+    loanAmount: null,
+    loanRate: null,
+    loanMethod: '',
+    loanMonths: null,
+    loanStart: '',
   })
   formError.value = null
   formOpen.value = true
@@ -245,6 +256,11 @@ function openEdit(w) {
     openingBalance: isLiability(w.type) ? -(w.openingBalance || 0) : w.openingBalance || 0,
     openingDate: w.openingDate || '',
     currentValue: w.currentValue ?? null,
+    loanAmount: w.loanAmount ?? null,
+    loanRate: w.loanRate ?? null,
+    loanMethod: w.loanMethod || '',
+    loanMonths: w.loanMonths ?? null,
+    loanStart: w.loanStart || '',
   })
   formError.value = null
   formOpen.value = true
@@ -258,6 +274,7 @@ async function submit() {
   }
   submitting.value = true
   const magnitude = Number(form.openingBalance) || 0
+  const isLoan = form.type === 'LOAN'
   const payload = {
     type: form.type,
     name: form.name.trim(),
@@ -271,6 +288,11 @@ async function submit() {
       form.type === 'INVEST' && form.currentValue !== '' && form.currentValue != null
         ? Number(form.currentValue)
         : null,
+    loanAmount: isLoan && form.loanAmount ? Number(form.loanAmount) : null,
+    loanRate: isLoan && form.loanRate !== null && form.loanRate !== '' ? Number(form.loanRate) : null,
+    loanMethod: isLoan && form.loanMethod ? form.loanMethod : null,
+    loanMonths: isLoan && form.loanMonths ? Number(form.loanMonths) : null,
+    loanStart: isLoan && form.loanStart ? form.loanStart : null,
   }
   try {
     if (editId.value) await accountApi.updateWallet(editId.value, payload)
@@ -297,6 +319,9 @@ async function remove(w) {
 function cardTypeLabel(v) {
   return v === 'CHECK' ? '체크' : v === 'CREDIT' ? '신용' : ''
 }
+function loanMethodLabel(v) {
+  return v === 'EQUAL_PAYMENT' ? '원리금균등' : v === 'EQUAL_PRINCIPAL' ? '원금균등' : v === 'BULLET' ? '만기일시' : ''
+}
 
 onMounted(async () => {
   await load()
@@ -362,6 +387,10 @@ onBeforeUnmount(() => sortable?.destroy())
                 >{{ revealedAccts.has(w.id) ? '🙈' : '👁' }}</button>
               </template>
               <template v-if="w.type === 'INVEST'"> · 투자금 {{ won(w.investedAmount) }}</template>
+              <template v-if="w.type === 'LOAN'">
+                <span v-if="w.loanAmount"> · 실행 {{ won(w.loanAmount) }}원</span>
+                <span v-if="w.loanRate"> · {{ w.loanRate }}%<span v-if="w.loanMethod"> / {{ loanMethodLabel(w.loanMethod) }}</span></span>
+              </template>
             </span>
           </div>
           <div class="balance-wrap">
@@ -458,6 +487,33 @@ onBeforeUnmount(() => sortable?.destroy())
               </template>
               <label>기준일<input v-model="form.openingDate" type="date" :disabled="submitting" /></label>
 
+              <!-- 대출 전용 -->
+              <template v-if="form.type === 'LOAN'">
+                <label>대출 실행 금액(원금)
+                  <input v-model.number="form.loanAmount" type="number" min="0"
+                    placeholder="처음 빌린 금액 (예: 10000000)" :disabled="submitting" />
+                </label>
+                <label>연이자율(%)
+                  <input v-model.number="form.loanRate" type="number" min="0" max="100" step="0.01"
+                    placeholder="예: 5.25" :disabled="submitting" />
+                </label>
+                <label>상환방식
+                  <select v-model="form.loanMethod" :disabled="submitting">
+                    <option value="">(선택 안 함)</option>
+                    <option value="EQUAL_PAYMENT">원리금균등상환</option>
+                    <option value="EQUAL_PRINCIPAL">원금균등상환</option>
+                    <option value="BULLET">만기일시상환</option>
+                  </select>
+                </label>
+                <label>대출기간(개월)
+                  <input v-model.number="form.loanMonths" type="number" min="1"
+                    placeholder="예: 120 (10년)" :disabled="submitting" />
+                </label>
+                <label>대출시작일
+                  <input v-model="form.loanStart" type="date" :disabled="submitting" />
+                </label>
+              </template>
+
               <p v-if="formError" class="msg error">{{ formError }}</p>
 
               <div class="buttons">