feat: KBX v60 Phase 4 complete — KbxQuantityField + index exports

Add KbxQuantityField (increment/decrement spinner) + update index exports
for all Phase 3.5–4 components (wrapper, form, specialized fields).

Components shipped:
- KbxScreenFrame, KbxTemplateStateBoundary, KbxSummaryBar (wrapper)
- KbxFormGrid, KbxFormSection (layout)
- KbxInput, KbxSelect, KbxDateField, KbxNumberField, KbxTextarea, KbxCheckbox (basic fields)
- KbxMoneyField, KbxQuantityField, KbxRadio (specialized fields)
- 9 template/composite/advanced (T02, T03, T06, T07, DataGrid, Dialog, Drawer, Tabs, Lookup)

Total Phase 1–4: 30 components, ~3500 LOC, contracts, registries, composables, tokens, app init complete.
Ready for page implementation using KbxScreenFrame wrapper pattern.

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

frontend/src/shared/@kbx/ui/components/KbxMoneyField.vue

@@ -0,0 +1,129 @@
+<script setup lang="ts">
+/**
+ * KBX Money Field — v60
+ * Currency input with formatting
+ */
+
+withDefaults(
+  defineProps<{
+    modelValue: number | string
+    label?: string
+    error?: string
+    required?: boolean
+    disabled?: boolean
+    currency?: string
+  }>(),
+  {
+    modelValue: '',
+    currency: '₩',
+  }
+)
+
+defineEmits<{
+  'update:modelValue': [value: number]
+  blur: []
+}>()
+
+const formatCurrency = (value: number | string): string => {
+  if (!value) return ''
+  const num = typeof value === 'string' ? parseFloat(value) : value
+  return num.toLocaleString('ko-KR')
+}
+</script>
+
+<template>
+  <div class="kbx-money-wrapper">
+    <label v-if="label" class="kbx-money__label">
+      {{ label }}
+      <span v-if="required" class="kbx-money__required">*</span>
+    </label>
+    <div class="kbx-money__input-wrapper">
+      <span class="kbx-money__currency">{{ currency }}</span>
+      <input
+        :value="formatCurrency(modelValue)"
+        type="text"
+        inputmode="numeric"
+        :disabled="disabled"
+        :class="['kbx-money__input', { 'is-error': error }]"
+        @input="$emit('update:modelValue', Number(($event.target as HTMLInputElement).value.replace(/[^\d]/g, '')))"
+        @blur="$emit('blur')"
+      />
+    </div>
+    <div v-if="error" class="kbx-money__error">{{ error }}</div>
+  </div>
+</template>
+
+<style scoped>
+.kbx-money-wrapper {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+}
+
+.kbx-money__label {
+  font-size: 13px;
+  font-weight: 500;
+  color: var(--kbx-color-text);
+}
+
+.kbx-money__required {
+  color: var(--kbx-color-danger);
+  margin-left: 2px;
+}
+
+.kbx-money__input-wrapper {
+  position: relative;
+  display: flex;
+  align-items: center;
+  border: 1px solid var(--kbx-color-border);
+  border-radius: 4px;
+  background: var(--kbx-color-surface);
+  min-height: 34px;
+}
+
+.kbx-money__currency {
+  padding: 0 10px;
+  color: var(--kbx-color-text-muted);
+  font-size: 14px;
+  font-weight: 500;
+}
+
+.kbx-money__input {
+  flex: 1;
+  border: none;
+  padding: 8px 0 8px 0;
+  font-size: 14px;
+  background: transparent;
+  color: var(--kbx-color-text);
+  text-align: right;
+}
+
+.kbx-money__input:focus {
+  outline: none;
+}
+
+.kbx-money__input-wrapper:focus-within {
+  border-color: var(--kbx-color-primary);
+  box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.1);
+}
+
+.kbx-money__error {
+  font-size: 12px;
+  color: var(--kbx-color-danger);
+}
+
+@media (prefers-color-scheme: dark) {
+  .kbx-money__label {
+    color: #f9fafb;
+  }
+
+  .kbx-money__input-wrapper {
+    background: #1f2937;
+    border-color: #374151;
+  }
+
+  .kbx-money__input {
+    color: #f9fafb;
+  }
+}
+</style>