refactor(dry-F2): centralize shared UI primitives (relative-time, toast, download-status)

- utils/date.js: add formatRelative(iso, {future,nullText}); migrate 6 sites
  (SourceRow, SubscriptionsTab, SourceHealthDot, SchedulerStatusBar +
  thin adapters in BackupRunsTable/SystemActivityTab for their '—' null text).
  PostCard (30d->absolute) and CredentialCard (mo/y buckets) intentionally
  keep bespoke formatters.
- utils/toast.js: toast(opts) wraps the globalThis.window?.__fcToast?.(...)
  incantation; migrate 63 call sites across 24 files.
- utils/downloadStatus.js: single source for the download-event status enum
  -> label/color/icon; collapse the 3 duplicate maps (DownloadStatChips,
  DownloadsFilterPopover, DownloadEventRow).

Net -33 lines. Platform metadata was already centralized in platformColor.js.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/components/downloads/DownloadDetailModal.vue

@@ -101,6 +101,7 @@
 </template>
 
 <script setup>
+import { toast } from '../../utils/toast.js'
 import { computed } from 'vue'
 
 import { copyText } from '../../utils/clipboard.js'
@@ -133,9 +134,9 @@ const allDiagnostics = computed(() => {
 async function onCopy(label, text) {
   try {
     await copyText(text || '')
-    window.__fcToast?.({ text: `${label} copied`, type: 'success' })
+    toast({ text: `${label} copied`, type: 'success' })
   } catch (e) {
-    window.__fcToast?.({ text: `Copy failed: ${e.message}`, type: 'error' })
+    toast({ text: `Copy failed: ${e.message}`, type: 'error' })
   }
 }
 

frontend/src/components/downloads/DownloadEventRow.vue

@@ -86,11 +86,13 @@
 </template>
 
 <script setup>
+import { toast } from '../../utils/toast.js'
 import { computed, ref } from 'vue'
 import { RouterLink } from 'vue-router'
 
 import PlatformChip from '../subscriptions/PlatformChip.vue'
 import { useSourcesStore } from '../../stores/sources.js'
+import { downloadStatusColor, downloadStatusIcon, downloadStatusLabel } from '../../utils/downloadStatus.js'
 
 const props = defineProps({ event: { type: Object, required: true } })
 defineEmits(['open'])
@@ -98,16 +100,9 @@ defineEmits(['open'])
 const sourcesStore = useSourcesStore()
 const retrying = ref(false)
 
-const _STATUS = {
-  ok:      { color: 'success', icon: 'mdi-check-circle',    label: 'Completed' },
-  error:   { color: 'error',   icon: 'mdi-alert-circle',    label: 'Failed' },
-  running: { color: 'info',    icon: 'mdi-progress-clock',  label: 'Running' },
-  pending: { color: 'grey',    icon: 'mdi-clock-outline',   label: 'Queued' },
-  skipped: { color: 'warning', icon: 'mdi-skip-next',       label: 'Skipped' },
-}
-const statusColor = computed(() => _STATUS[props.event.status]?.color || 'grey')
-const statusIcon = computed(() => _STATUS[props.event.status]?.icon || 'mdi-help-circle')
-const statusLabel = computed(() => _STATUS[props.event.status]?.label || props.event.status)
+const statusColor = computed(() => downloadStatusColor(props.event.status))
+const statusIcon = computed(() => downloadStatusIcon(props.event.status))
+const statusLabel = computed(() => downloadStatusLabel(props.event.status))
 
 function fmtTime(iso) {
   if (!iso) return '—'
@@ -131,12 +126,12 @@ async function onRetry() {
   retrying.value = true
   try {
     await sourcesStore.checkNow(props.event.source_id)
-    globalThis.window?.__fcToast?.({
+    toast({
       text: `Source check re-queued`, type: 'success',
     })
   } catch (e) {
     const isInFlight = !!e?.body?.download_event_id
-    globalThis.window?.__fcToast?.({
+    toast({
       text: isInFlight ? 'Already running' : `Retry failed: ${e?.detail || e?.message || e}`,
       type: isInFlight ? 'info' : 'error',
     })