feat(user): about software page, enamad badge, and deal sheet UI polish

Add public about-software flow, login-only enamad, and deal buy/sell UI refinements for the store user app.

src/components/EnamadBadge.vue

@@ -0,0 +1,70 @@
+<template>
+  <a
+    v-if="href && src"
+    referrerpolicy="origin"
+    target="_blank"
+    rel="noopener noreferrer"
+    :href="href"
+    class="enamad-badge"
+    :class="`enamad-badge--${size}`"
+  >
+    <img
+      referrerpolicy="origin"
+      :src="src"
+      alt="enamad"
+      class="enamad-badge__img"
+      :code="code || undefined"
+    />
+  </a>
+</template>
+
+<script lang="ts" setup>
+import { computed } from 'vue'
+import { useSettingsStore } from '@/store/settingsStore'
+
+withDefaults(
+  defineProps<{
+    size?: 'sm' | 'lg'
+  }>(),
+  { size: 'sm' },
+)
+
+const settingsStore = useSettingsStore()
+
+const href = computed(() =>
+  String(settingsStore.getSettingByKey('enamad_url') ?? '').trim(),
+)
+const src = computed(() =>
+  String(settingsStore.getSettingByKey('enamad_logo') ?? '').trim(),
+)
+const code = computed(() => {
+  try {
+    const u = new URL(href.value || src.value)
+    return u.searchParams.get('Code') || u.searchParams.get('code') || ''
+  } catch {
+    return ''
+  }
+})
+</script>
+
+<style scoped lang="less">
+.enamad-badge {
+  display: inline-flex;
+  line-height: 0;
+}
+
+.enamad-badge__img {
+  width: auto;
+  cursor: pointer;
+  object-fit: contain;
+}
+
+.enamad-badge--sm .enamad-badge__img {
+  height: 40px;
+}
+
+.enamad-badge--lg .enamad-badge__img {
+  height: 120px;
+  max-width: 100%;
+}
+</style>