feat(family): the promotion engine - triggers, the three criteria, the decision log and undo (milestone 463 step 3, #4989)

The agent promotes a family idea when all three criteria hold, and no person approves it. The criteria are product text: services/family.py states them, and the promote tool's docstring names every criterion the service enforces.

- Criteria: each one vetoes on its own when its reasoning is blank. Platform terms also needs an applies-when and a platform scope; proven also needs named evidence. A veto keeps the idea a candidate and is logged, so it becomes precedent.
- Precedent: every promotion stores the decisions on the nearest ideas by meaning, plus any the caller names.
- Promotion sets canon, the applicability test and the platform scope, and opens an unassessed ledger row for each member project the promoter can write. Re-promotion moves the version past every version the idea has held.
- Retire and undo: undo reverses only the latest idea-level decision, restores its recorded before-state, and logs itself with the undone decision as its precedent. Settled here: leaving canon closes the unassessed rows but keeps the judged ones, which read as needing a recheck after a re-promotion.
- Triggers open evaluations but never promote:
  - a cross-project lineage citation ("matching #N") on a note or task write;
  - a same-meaning record in another project on a shared platform, on create, at 0.80 (measured: the known pattern's builds scored 0.79-0.82, an unrelated project's best match 0.65);
  - a milestone closing on a platform.
  Each fails open and rides the response as family_hint.
- Doors: seven MCP tools, /api/family REST endpoints, and a Family page (nav, /family) showing the criteria, the ideas, and the decision log with undo and retire.
- utils/recordHref.ts holds the one copy of "where a record opens", now shared with LessonDetailView.

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

frontend/src/views/LessonDetailView.vue

@@ -41,6 +41,7 @@ import { DEAD_WEIGHT_ADVICE } from "@/utils/deadWeight";
 import { useToastStore } from "@/stores/toast";
 import { renderMarkdown } from "@/utils/markdown";
 import { canWriteRecord } from "@/utils/permission";
+import { recordHref } from "@/utils/recordHref";
 
 const route = useRoute();
 const router = useRouter();
@@ -59,14 +60,6 @@ const insightHtml = computed(() =>
   lesson.value?.insight ? renderMarkdown(lesson.value.insight) : "",
 );
 
-/** Where each source opens. A task and a note live at different routes, and a
- *  link that guesses wrong is worse than one that is plain. */
-function sourceHref(rec: { id: number; is_task?: boolean; note_type?: string }) {
-  if (rec.is_task) return `/tasks/${rec.id}`;
-  if (rec.note_type === "snippet") return `/snippets/${rec.id}`;
-  if (rec.note_type === "lesson") return `/lessons/${rec.id}`;
-  return `/notes/${rec.id}`;
-}
 
 const canWrite = computed(() => canWriteRecord(lesson.value?.permission));
 
@@ -193,7 +186,7 @@ onMounted(load);
         <h2 class="ld-panel-label">Learned from</h2>
         <ul class="ld-sources">
           <li v-for="rec in lesson.learned_from_records" :key="rec.id">
-            <router-link :to="sourceHref(rec)" class="ld-link">
+            <router-link :to="recordHref(rec)" class="ld-link">
               {{ rec.title }}
             </router-link>
             <span v-if="rec.status" class="ld-source-status">{{ rec.status }}</span>