feat(kiwi-fe): add useOrchUsage composable with opt-in localStorage persistence

frontend/src/composables/useOrchUsage.ts

@@ -0,0 +1,55 @@
+/**
+ * useOrchUsage — reactive cf-orch call budget for lifetime/founders users.
+ *
+ * Auto-fetches on mount when enabled. Returns null for subscription users (no cap applies).
+ * The `enabled` state is persisted to localStorage — users opt in to seeing the pill.
+ */
+import { ref, computed, onMounted } from 'vue'
+import { getOrchUsage, type OrchUsage } from '@/services/api'
+
+const STORAGE_KEY = 'kiwi:orchUsagePillEnabled'
+
+// Shared singleton state across all component instances
+const usage = ref<OrchUsage | null>(null)
+const loading = ref(false)
+const enabled = ref<boolean>(
+  typeof localStorage !== 'undefined'
+    ? localStorage.getItem(STORAGE_KEY) === 'true'
+    : false
+)
+
+async function fetchUsage(): Promise<void> {
+  loading.value = true
+  try {
+    usage.value = await getOrchUsage()
+  } catch {
+    // Non-blocking — UI stays hidden on error
+    usage.value = null
+  } finally {
+    loading.value = false
+  }
+}
+
+function setEnabled(val: boolean): void {
+  enabled.value = val
+  localStorage.setItem(STORAGE_KEY, String(val))
+  if (val && usage.value === null && !loading.value) {
+    fetchUsage()
+  }
+}
+
+const resetsLabel = computed<string>(() => {
+  if (!usage.value?.resets_on) return ''
+  const d = new Date(usage.value.resets_on + 'T00:00:00')
+  return d.toLocaleDateString(undefined, { month: 'short', day: 'numeric' })
+})
+
+export function useOrchUsage() {
+  onMounted(() => {
+    if (enabled.value && usage.value === null && !loading.value) {
+      fetchUsage()
+    }
+  })
+
+  return { usage, loading, enabled, setEnabled, fetchUsage, resetsLabel }
+}