feat(family): the shape ledger judges against family ideas, across languages (milestone 463 step 5, #4991)

- classify_shapes takes idea_id: the shape is judged against the idea's
  reference in its language, or its first.
- A shape classified against a canon idea's reference moves the project's
  adoption row (instance -> adopted, variant -> variant). Withdrawing the
  shapes that gave an answer returns it to unassessed. This runs on
  classify_shapes, the sweep, confirm_proposals and the coverage refresh.
- assess and undo refuse an answer the shapes contradict. A conflict
  resolution re-judges the variant shapes on both sides.
- The proposer's family arm offers a canon idea's reference on a shared
  platform, in any language. It proposes only when the reference is the top
  hit over every readable snippet and scores at least 0.70. The pairs this
  was measured on are recorded beside _FAMILY_FLOOR. The proposer is now v6.
- The matrix cell shows the code that answers it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

frontend/src/api/family.ts

@@ -126,6 +126,8 @@ export interface AdoptionCell {
   /** Answered against a canon version that is not the current one. */
   needs_recheck: boolean;
   owed_task: { id: number; title: string; status: string } | null;
+  /** Live shapes in the project classified against one of the idea's references. */
+  shapes: { path: string; symbol: string; status: "canonical" | "instance" | "variant" }[];
 }
 
 export interface MatrixIdea {

frontend/src/components/FamilyAdoptionMatrix.vue

@@ -218,6 +218,15 @@ defineExpose({ load });
             </router-link>
             <span class="fam-muted">({{ selected.owed_task.status.replace("_", " ") }})</span>
           </p>
+          <div v-if="selected.shapes.length" class="fam-detail-shapes">
+            <p>In this project's code — the shape ledger classifies:</p>
+            <ul>
+              <li v-for="s in selected.shapes" :key="`${s.path}::${s.symbol}`">
+                <code>{{ s.path }} · {{ s.symbol }}</code>
+                <span class="fam-muted">{{ s.status === "variant" ? "variant" : "instance" }}</span>
+              </li>
+            </ul>
+          </div>
           <p v-if="selected.assessed_at" class="fam-muted">
             Answered {{ fmtStamp(selected.assessed_at) }}
             <template v-if="selected.decided_via">by the {{ selected.decided_via }}</template>
@@ -320,6 +329,9 @@ button.fam-cell:hover { background: var(--fs-surface-hover); }
 .fam-detail p { margin: 0.4rem 0 0; font-size: 0.875rem; }
 .fam-detail-reason { color: var(--fs-text-primary); }
 .fam-detail-recheck { color: var(--fs-text-secondary); }
+.fam-detail-shapes ul { margin: 0.25rem 0 0; padding-left: 1.1rem; font-size: 0.85rem; }
+.fam-detail-shapes li { display: flex; flex-wrap: wrap; align-items: baseline; gap: 0 0.5rem; overflow-wrap: anywhere; }
+.fam-detail-shapes code { font-family: var(--fs-font-mono); }
 .fam-outcomes { margin-top: 0.75rem; font-size: 0.85rem; color: var(--fs-text-secondary); }
 .fam-outcomes summary { cursor: pointer; color: var(--fs-text-secondary); }
 .fam-outcomes dl { margin: 0.5rem 0 0; }