feat(ui): 계좌/분류 선택을 바텀시트로 (정기결제 폼)

- BottomSheet.vue: 아래에서 올라오는 콘텐츠 높이 시트(재사용)
- SheetSelect.vue: 필드형 트리거 → 바텀시트 단일 선택(계좌/카드)
- 정기결제 폼: 계좌는 SheetSelect, 분류는 트리거 → 시트 안 CategoryPicker
  (선택 전에는 목록 미노출, 선택 시 값 채움)

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/ui/BottomSheet.vue

@@ -0,0 +1,93 @@
+<script setup>
+// 아래에서 올라오는 바텀시트(콘텐츠 높이). 선택 항목(계좌·분류 등)에 사용.
+defineProps({
+  modelValue: { type: Boolean, required: true },
+  title: { type: String, default: '' },
+})
+defineEmits(['update:modelValue'])
+</script>
+
+<template>
+  <Teleport to="body">
+    <Transition name="bs">
+      <div v-if="modelValue" class="bs-wrap" @click.self="$emit('update:modelValue', false)">
+        <div class="bs-panel" role="dialog" aria-modal="true">
+          <div class="bs-grip" @click="$emit('update:modelValue', false)"></div>
+          <div class="bs-head">
+            <span class="bs-title">{{ title }}</span>
+            <button type="button" class="bs-close" aria-label="닫기" @click="$emit('update:modelValue', false)">×</button>
+          </div>
+          <div class="bs-body"><slot /></div>
+        </div>
+      </div>
+    </Transition>
+  </Teleport>
+</template>
+
+<style scoped>
+.bs-wrap {
+  position: fixed;
+  inset: 0;
+  z-index: 1100;
+  background: rgba(0, 0, 0, 0.4);
+  display: flex;
+  align-items: flex-end;
+}
+.bs-panel {
+  width: 100%;
+  max-width: 560px;
+  margin: 0 auto;
+  background: var(--color-background);
+  border-radius: 16px 16px 0 0;
+  max-height: 85vh;
+  overflow-y: auto;
+  padding: 0.4rem 1.1rem calc(1rem + env(safe-area-inset-bottom, 0));
+  box-shadow: 0 -8px 30px rgba(0, 0, 0, 0.25);
+}
+.bs-grip {
+  width: 40px;
+  height: 4px;
+  border-radius: 2px;
+  background: var(--color-border);
+  margin: 0.4rem auto 0.2rem;
+  cursor: pointer;
+}
+.bs-head {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: 0.3rem 0 0.6rem;
+}
+.bs-title {
+  font-weight: 700;
+  font-size: 1rem;
+}
+.bs-close {
+  border: 0;
+  background: transparent;
+  font-size: 1.4rem;
+  line-height: 1;
+  color: var(--color-text);
+  cursor: pointer;
+}
+.bs-enter-active {
+  transition: background 0.2s ease;
+}
+.bs-leave-active {
+  transition: background 0.18s ease;
+}
+.bs-enter-from,
+.bs-leave-to {
+  background: rgba(0, 0, 0, 0);
+}
+.bs-enter-active .bs-panel {
+  transition: transform 0.28s cubic-bezier(0.32, 0.72, 0, 1);
+}
+.bs-leave-active .bs-panel {
+  transition: transform 0.2s cubic-bezier(0.4, 0, 1, 1);
+}
+.bs-enter-from .bs-panel,
+.bs-leave-to .bs-panel {
+  transform: translateY(100%);
+}
+</style>

src/components/ui/SheetSelect.vue

@@ -0,0 +1,113 @@
+<script setup>
+// 필드형 트리거를 누르면 바텀시트로 옵션을 보여주고 단일 선택. (계좌·카드 선택 등)
+import { computed, ref } from 'vue'
+import BottomSheet from './BottomSheet.vue'
+
+const props = defineProps({
+  modelValue: { type: [String, Number], default: '' },
+  options: { type: Array, default: () => [] }, // [{ value, label }]
+  placeholder: { type: String, default: '선택하세요' },
+  title: { type: String, default: '선택' },
+  disabled: { type: Boolean, default: false },
+  emptyText: { type: String, default: '선택할 항목이 없습니다' },
+})
+const emit = defineEmits(['update:modelValue'])
+
+const open = ref(false)
+const selected = computed(() => props.options.find((o) => o.value === props.modelValue) || null)
+function pick(o) {
+  emit('update:modelValue', o.value)
+  open.value = false
+}
+</script>
+
+<template>
+  <button
+    type="button" class="ss-trigger" :class="{ empty: !selected }"
+    :disabled="disabled" @click="open = true"
+  >
+    <span class="ss-label">{{ selected ? selected.label : placeholder }}</span>
+    <span class="ss-caret">▾</span>
+  </button>
+
+  <BottomSheet v-model="open" :title="title">
+    <ul v-if="options.length" class="ss-list">
+      <li v-for="o in options" :key="o.value">
+        <button
+          type="button" class="ss-opt" :class="{ active: o.value === modelValue }"
+          @click="pick(o)"
+        >
+          <span>{{ o.label }}</span>
+          <span v-if="o.value === modelValue" class="ss-check">✓</span>
+        </button>
+      </li>
+    </ul>
+    <p v-else class="ss-empty">{{ emptyText }}</p>
+  </BottomSheet>
+</template>
+
+<style scoped>
+.ss-trigger {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  gap: 0.5rem;
+  width: 100%;
+  padding: 0.55rem 0.75rem;
+  border: 1px solid var(--color-border);
+  border-radius: 6px;
+  background: var(--color-background-soft);
+  color: var(--color-text);
+  font-size: 0.9rem;
+  cursor: pointer;
+  text-align: left;
+}
+.ss-trigger:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+}
+.ss-trigger.empty .ss-label {
+  opacity: 0.5;
+}
+.ss-label {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+.ss-caret {
+  opacity: 0.5;
+  font-size: 0.8rem;
+  flex-shrink: 0;
+}
+.ss-list {
+  list-style: none;
+  margin: 0;
+  padding: 0;
+}
+.ss-opt {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  width: 100%;
+  padding: 0.85rem 0.4rem;
+  border: 0;
+  border-bottom: 1px solid var(--color-border);
+  background: transparent;
+  color: var(--color-text);
+  font-size: 0.95rem;
+  cursor: pointer;
+  text-align: left;
+}
+.ss-opt.active {
+  color: hsla(160, 100%, 37%, 1);
+  font-weight: 700;
+}
+.ss-check {
+  color: hsla(160, 100%, 37%, 1);
+}
+.ss-empty {
+  padding: 1.2rem 0.4rem;
+  opacity: 0.6;
+  text-align: center;
+}
+</style>