feat: the front door says whether ingestion is working (milestone 387 step B3)

The step phase A was building toward. A1 made the gated count true, A2
made it a durable state, A3 made it visible in Subscriptions — but
Subscriptions is where you go once you already suspect something. This
is the line that reaches someone who wasn't looking.

A thin grey strip above the feed, front door only: last check, sources
failing, sources you can't see. Only the actionable items take a
colour, and nothing renders at zero — a permanent "0 failing" trains
you to skip the line, which would hide the real number when it appears.

Two predicates, defined once. The ribbon counts and the surfaces it
links to have to agree on what "failing" and "no access" MEAN, or the
ribbon says 3 and the card shows 4. They live in db_helpers, which
exists for exactly this reason (its docstring: divergent copies are how
the race bugs crept in). Not in source_service, because
scheduler_service needs them too and source_service already imports
scheduler_service — the other direction is a cycle.

Counting deliberately spans all ENABLED sources rather than the
auto_check subset scheduler_status already walks: a source erroring on
a manual-only artist is still erroring. Disabled sources count for
nothing, which is what makes issue 1285 the real escape hatch for a sub
you stopped paying for.

Extends the existing schedule-status endpoint rather than adding a
parallel aggregate — the store already fetches it. Two scalar COUNTs.

The status filter is now URL-addressable, which it had to be for the
ribbon's links to land anywhere: a count that drops you on an
unfiltered list makes the reader redo the filtering the ribbon just
did. Mirrors how artistFilter already reads from route.query.

Front-door-only via a route prop, not a route.name check, so the view
doesn't need to know what it's mounted as and the router states the
intent in one place. Inside Browse's Posts tab you're looking FOR
something and the hub is one click away.

The fetch is swallowed on mount by design (rule 164): this is an aside,
and the feed must render whether or not the status call succeeds.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LNXXULQDjVZmbuNa2G9mD9

frontend/src/components/posts/FeedStatusRibbon.vue

@@ -0,0 +1,80 @@
+<template>
+  <!-- Renders nothing at all until it has something true to say. A ribbon that
+       shows a skeleton or an error on the front door would make the app look
+       broken every cold load; the feed is the point, this is an aside. -->
+  <div v-if="status" class="fc-ribbon">
+    <span class="fc-ribbon__item">
+      <v-icon size="x-small">mdi-clock-outline</v-icon>
+      Checked {{ lastCheckedLabel }}
+    </span>
+
+    <RouterLink
+      v-if="failing" class="fc-ribbon__item fc-ribbon__item--err"
+      :to="{ path: '/subscriptions', query: { status: 'errors' } }"
+    >
+      <v-icon size="x-small">mdi-alert-circle-outline</v-icon>
+      {{ failing }} {{ failing === 1 ? 'source is' : 'sources are' }} failing
+    </RouterLink>
+
+    <!-- The reason this ribbon exists. Phase A made "we can't see this
+         creator's posts" a durable fact; without a line here it stays buried
+         three clicks into Subscriptions, which is exactly where nobody looks
+         until they already suspect something. -->
+    <RouterLink
+      v-if="noAccess" class="fc-ribbon__item fc-ribbon__item--gated"
+      :to="{ path: '/subscriptions', query: { status: 'no_access' } }"
+    >
+      <v-icon size="x-small">mdi-lock-outline</v-icon>
+      {{ noAccess }} you can't see
+    </RouterLink>
+  </div>
+</template>
+
+<script setup>
+import { computed, onMounted } from 'vue'
+import { storeToRefs } from 'pinia'
+
+import { useSourcesStore } from '../../stores/sources.js'
+import { formatRelative } from '../../utils/date.js'
+
+const store = useSourcesStore()
+const { scheduleStatus: status } = storeToRefs(store)
+
+const failing = computed(() => status.value?.failing_sources || 0)
+const noAccess = computed(() => status.value?.no_access_sources || 0)
+const lastCheckedLabel = computed(() =>
+  formatRelative(status.value?.last_tick_at, { nullText: 'never' }),
+)
+
+onMounted(() => {
+  // Swallowed on purpose: this is an aside on the front door, and the feed
+  // must render whether or not the status call succeeds (rule #164 — a
+  // genuinely-external-ish fact degrades to absent, it never gates the page).
+  store.loadScheduleStatus().catch(() => {})
+})
+</script>
+
+<style scoped>
+.fc-ribbon {
+  display: flex;
+  align-items: center;
+  flex-wrap: wrap;
+  gap: 4px 14px;
+  padding: 2px 0 10px;
+  font-size: 0.78rem;
+  color: rgb(var(--v-theme-on-surface-variant));
+}
+.fc-ribbon__item {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  color: inherit;
+  text-decoration: none;
+}
+/* Only the actionable items take a colour, so a healthy instance reads as one
+   quiet grey line rather than a status dashboard. */
+.fc-ribbon__item--err { color: rgb(var(--v-theme-error)); }
+.fc-ribbon__item--gated { color: rgb(var(--v-theme-info)); }
+.fc-ribbon__item--err:hover,
+.fc-ribbon__item--gated:hover { text-decoration: underline; }
+</style>

frontend/src/components/subscriptions/SubscriptionsTab.vue

@@ -368,7 +368,19 @@ const platformsStore = usePlatformsStore()
 const importStore = useImportStore()
 
 const search = ref('')
-const statusFilter = ref('all')
+// URL-addressable (#387 B3) so the front-door status ribbon can link straight
+// to "the sources this number is about" — a count that lands you on an
+// unfiltered list makes the reader do the filtering the ribbon just did.
+// Mirrors how artistFilter already reads from route.query below.
+const statusFilter = computed({
+  get: () => route.query.status || 'all',
+  set: (v) => {
+    const q = { ...route.query }
+    if (!v || v === 'all') delete q.status
+    else q.status = v
+    router.replace({ query: q })
+  },
+})
 const needsAttention = ref(false)
 const expanded = ref([])
 const selected = ref([])

frontend/src/router.js

@@ -35,7 +35,10 @@ const routes = [
   //
   // No stickyChrome: unlike Browse/Gallery/Settings this view has no sticky
   // sub-header for the nav to butt against, so the nav keeps its normal fade.
-  { path: '/latest', name: 'latest', component: PostsView, meta: { title: 'Latest', navOrder: 5 } },
+  // `props` turns on the ingestion-status ribbon (#387 B3). Only here: inside
+  // Browse's Posts tab the same view renders without it.
+  { path: '/latest', name: 'latest', component: PostsView, props: { statusRibbon: true },
+    meta: { title: 'Latest', navOrder: 5 } },
 
   // FC-2: image backbone
   { path: '/showcase', name: 'showcase', component: ShowcaseView, meta: { title: 'Showcase', navOrder: 10 } },

frontend/src/views/PostsView.vue

@@ -49,6 +49,8 @@
 
     <!-- Normal feed -->
     <template v-else>
+      <FeedStatusRibbon v-if="statusRibbon" />
+
       <PostsFilterBar
         :artist-id="artistFilter"
         :platform="platformFilter"
@@ -89,6 +91,16 @@ import { useRoute, useRouter } from 'vue-router'
 import { usePostsStore } from '../stores/posts.js'
 import PostsFilterBar from '../components/posts/PostsFilterBar.vue'
 import PostCard from '../components/posts/PostCard.vue'
+import FeedStatusRibbon from '../components/posts/FeedStatusRibbon.vue'
+
+// The ingestion-status ribbon is a FRONT-DOOR concern, not a feed concern —
+// inside Browse's Posts tab you are looking FOR something, and the Subscriptions
+// hub is a click away. Passed as a route prop rather than sniffed from
+// route.name so the view does not have to know what it is mounted as, and so
+// the router file states the intent in one place.
+defineProps({
+  statusRibbon: { type: Boolean, default: false },
+})
 
 const route = useRoute()
 const router = useRouter()

frontend/test/components/feedStatusRibbon.spec.js

@@ -0,0 +1,76 @@
+// @vitest-environment happy-dom
+import { describe, it, expect, beforeEach, afterEach, vi } from 'vitest'
+
+import FeedStatusRibbon from '../../src/components/posts/FeedStatusRibbon.vue'
+import { useSourcesStore } from '../../src/stores/sources.js'
+import { freshPinia, mountComponent } from '../support/mountComponent.js'
+
+// #387 B3. This ribbon is the ONLY place phase A's work reaches someone who
+// wasn't already looking for it, so what it does and does not say is the whole
+// feature. These pin: it stays silent when it has nothing true to report, it
+// keeps "failing" and "no access" as separate claims, and it never renders a
+// zero — a "0 failing" on the front door is noise that trains you to ignore
+// the line, which is exactly what would hide the real number later.
+
+function mountWith (status) {
+  const pinia = freshPinia()
+  useSourcesStore().scheduleStatus = status
+  return mountComponent(FeedStatusRibbon, { pinia })
+}
+
+describe('FeedStatusRibbon', () => {
+  beforeEach(() => {
+    // The component fetches on mount and swallows failures by design; stub it
+    // so the assertions are about the seeded state, not a race with the call.
+    globalThis.fetch = vi.fn(async () => { throw new Error('offline') })
+  })
+  afterEach(() => vi.restoreAllMocks())
+
+  it('renders nothing before it has a status', () => {
+    const w = mountWith(null)
+    expect(w.find('.fc-ribbon').exists()).toBe(false)
+  })
+
+  it('a healthy instance is one quiet line, with no zeroes', () => {
+    const w = mountWith({
+      last_tick_at: new Date().toISOString(), failing_sources: 0, no_access_sources: 0,
+    })
+    expect(w.find('.fc-ribbon').exists()).toBe(true)
+    expect(w.text()).toContain('Checked')
+    // Assert on the claims, not on the digit — a just-now timestamp can render
+    // its own "0 minutes ago" and a substring check would catch that instead.
+    expect(w.text()).not.toContain('failing')
+    expect(w.text()).not.toContain("can't see")
+    expect(w.find('.fc-ribbon__item--err').exists()).toBe(false)
+    expect(w.find('.fc-ribbon__item--gated').exists()).toBe(false)
+  })
+
+  it('reports failing and no-access as two separate claims', () => {
+    const w = mountWith({
+      last_tick_at: new Date().toISOString(), failing_sources: 2, no_access_sources: 5,
+    })
+    expect(w.find('.fc-ribbon__item--err').text()).toContain('2 sources are failing')
+    expect(w.find('.fc-ribbon__item--gated').text()).toContain("5 you can't see")
+  })
+
+  it('no-access alone does not light the failing item', () => {
+    // The whole point of phase A: a paywalled creator is not a broken one.
+    const w = mountWith({
+      last_tick_at: new Date().toISOString(), failing_sources: 0, no_access_sources: 3,
+    })
+    expect(w.find('.fc-ribbon__item--err').exists()).toBe(false)
+    expect(w.find('.fc-ribbon__item--gated').exists()).toBe(true)
+  })
+
+  it('says "never" rather than a blank when nothing has ever run', () => {
+    const w = mountWith({ last_tick_at: null, failing_sources: 0, no_access_sources: 0 })
+    expect(w.text()).toContain('never')
+  })
+
+  it('singularises one failing source', () => {
+    const w = mountWith({
+      last_tick_at: new Date().toISOString(), failing_sources: 1, no_access_sources: 0,
+    })
+    expect(w.find('.fc-ribbon__item--err').text()).toContain('1 source is failing')
+  })
+})