feat: the announcement link, on the card and in a review queue (388 E5)

Rule 27 — E5's other half. The matcher can propose; this is where the operator
decides, and where an accepted link actually shows up.

**The review queue** (Settings → Ingestion & filters). Each proposal shows the
per-signal breakdown, not just the total: "why did it suggest this" is the
question the operator actually has, and a lone percentage cannot answer it. So
a row reads "72% · timing 95% · says so 60%", and the copy states outright that
a pair always needs two reasons — which is the property that stops a busy
posting day from producing false pairs.

The empty state says so explicitly. Nothing proposed is the EXPECTED state most
of the time, and an empty queue that looks like a failure invites turning the
threshold down until it produces noise.

**On the card**, both directions, and accepted links only: the teaser gets "The
full set is in Discord", the drop gets "Announced on Patreon". A pending
proposal is a question for the review queue, never a claim to render beside the
artwork — that distinction is the whole confirm-only design, so it is asserted
in the backend (only `linked` rows reach the payload) and again here.

One detail worth the comment it carries: the link's target is `{ query: {
post_id } }` with no name or path. In vue-router that means "the current route
with these query params", so it works identically from Latest and from Browse —
and, more usefully, the card never reaches for `useRoute()`, which it has no
other reason to know about and which is not available when it is mounted in a
test without a router.

Backend CI on 235393c was green: all 13 E5 tests and migration 0094.

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

frontend/src/components/posts/PostCard.vue

@@ -128,6 +128,25 @@
           @click="toggleDesc"
         >{{ descExpanded ? 'Show less' : 'Show more' }}</button>
 
+        <!-- #388 E5: the accepted announcement link, both directions. Only
+             ACCEPTED ones reach the payload, so anything rendered here is
+             something the operator agreed to — never a proposal. -->
+        <!-- A location with no name/path is "the current route, with these
+             query params" — so this works from Latest or Browse alike without
+             the card reaching for useRoute(), which it has no other reason to
+             know about. -->
+        <div v-if="associations.length" class="fc-post-card__assoc">
+          <RouterLink
+            v-for="a in associations" :key="a.id"
+            :to="{ query: { post_id: a.post_id } }"
+            class="fc-post-card__assoc-link"
+          >
+            <v-icon icon="mdi-link-variant" size="x-small" />
+            {{ a.role === 'announces'
+              ? 'The full set is in Discord' : 'Announced on Patreon' }}
+          </RouterLink>
+        </div>
+
         <!-- Off-platform file-host links (mega/gdrive/…) found in the body.
              Shown once expanded; clickable now, auto-downloaded by the worker
              slice. -->
@@ -234,6 +253,10 @@ const sortDateIso = computed(() => props.post.post_date || props.post.downloaded
 // Tuesday but gained images this morning" is the whole signal that chat
 // content is trickling in.
 const grewAt = computed(() => (synthesized.value ? props.post.last_grew_at : null))
+// #388 E5. Accepted links only — a pending proposal lives in the review queue,
+// never beside the artwork. Defaults to [] so a post dict from before the
+// feature (or composed by hand) renders without a link rather than throwing.
+const associations = computed(() => props.post.associations || [])
 const grewRelative = computed(() => (grewAt.value ? relativeFrom(grewAt.value) : ''))
 const absoluteDate = computed(() => new Date(sortDateIso.value).toLocaleString())
 function relativeFrom (iso) {
@@ -394,6 +417,17 @@ function formatBytes (n) {
 /* Growth is news, so it gets the accent the rest of the meta line doesn't —
    but it is still the meta line, not a badge competing with the artwork. */
 .fc-post-card__grew { color: rgb(var(--v-theme-accent)); }
+
+.fc-post-card__assoc { margin-top: 8px; }
+.fc-post-card__assoc-link {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  font-size: 0.8125rem;
+  color: rgb(var(--v-theme-accent));
+  text-decoration: none;
+}
+.fc-post-card__assoc-link:hover { text-decoration: underline; }
 .fc-post-card__date,
 .fc-post-card__meta { white-space: nowrap; }