diff --git a/packages/content/CHARTER.md b/packages/content/CHARTER.md
index 7a7e6d8..8cdd8d9 100644
--- a/packages/content/CHARTER.md
+++ b/packages/content/CHARTER.md
@@ -65,7 +65,7 @@ These exist so the template stays a **template**, not a half-finished product:
 | Total `.ts` LOC under `src/` | ≤ 6,000 | Readable in a half-day sitting |
 | Locales | 2 (`en`, `zh-CN`) | Proves multi-locale without becoming a translation project |
 | Dashboards | 3 | Today / Calendar / ROI — each shows a distinct widget class |
-| Flows | ≤ 5 | Event-driven only (no cron in spec v6); time-based work ships as record actions. Cap raised 4→5 (2026-06): the package already ships five distinct event-driven flows — signal→topic promotion, CTA default, publish approval, publication rollup, and lifecycle notifications (the latter was renamed from `stamp_lifecycle_timestamps` once timestamp-stamping moved into the piece hook). |
+| Flows | ≤ 5 | Event-driven only (no cron in spec v6); time-based work ships as record actions. The package ships four event-driven flows — signal→topic promotion, CTA default, publish approval, and lifecycle notifications (renamed from `stamp_lifecycle_timestamps` once timestamp-stamping moved into the piece hook). A former fifth, `publication_rollup`, was retired once the metric→publication→piece totals became native `Field.summary` roll-ups (its script-node "aggregations" never ran — the automation engine has no aggregate node). |
 | State machines | 2 | piece + signal |
 | Approval processes | 1 | publish gate |
 | Sharing rules | 1 | topic-scoped |
diff --git a/packages/content/src/hooks/index.ts b/packages/content/src/hooks/index.ts
index 2f1af87..5ff6662 100644
--- a/packages/content/src/hooks/index.ts
+++ b/packages/content/src/hooks/index.ts
@@ -4,8 +4,12 @@ import { pieceHook, signalHook } from '../objects/content_piece.hook';
 
 // NOTE: the metric → publication → piece totals (`total_views` etc.) are native
 // `Field.summary` roll-ups on content_publication / content_piece (#1870) — the
-// engine recomputes them server-side on child insert/update/delete. They are NOT
-// hook-maintained: a cross-object rollup write from a hook is unsupported in the
-// standalone QuickJS runtime (nested writes crash; `ctx.services.data` is
-// undefined inside it), which is why the declarative summary-field route is used.
+// engine recomputes them server-side on child insert/update/delete. A pure
+// sum/max like these is expressed declaratively as a `summary` field rather than
+// a hook because it needs to be delete-safe: the engine captures the child's FK
+// pre-image on delete and recomputes the parent, whereas an `afterDelete` hook
+// only receives `{ id }` and can't tell which parent to fix. (Nested cross-object
+// writes from hooks are now safe — framework#1867 is fixed — so a hook is the
+// right tool for a *non-aggregate* rollup; for these pure aggregates the summary
+// field stays the better fit.)
 export const allHooks = [pieceHook, signalHook];
diff --git a/packages/content/src/objects/content_publication.object.ts b/packages/content/src/objects/content_publication.object.ts
index f750c34..32d6c42 100644
--- a/packages/content/src/objects/content_publication.object.ts
+++ b/packages/content/src/objects/content_publication.object.ts
@@ -13,8 +13,9 @@ import { ObjectSchema, Field } from '@objectstack/spec/data';
  * them server-side from the child `content_metric` rows, and they cascade one
  * level up to the parent `content_piece`'s own `total_*` summaries. (A piece
  * with no publications yet has no child to trigger a recompute, so its rollups
- * read `null` until its first publication exists.) A hook can't maintain these —
- * a nested cross-object write is unsupported in the standalone runtime; see
+ * read `null` until its first publication exists.) These are declared as
+ * `summary` fields rather than hook-maintained because a pure aggregate needs a
+ * delete-safe recompute — which the engine does natively off the child FK; see
  * content/src/hooks/index.ts.
  */
 export const Publication = ObjectSchema.create({
@@ -67,9 +68,10 @@ export const Publication = ObjectSchema.create({
     // recomputes these server-side whenever a child `content_metric` row is
     // inserted/updated/deleted (FK `content_metric.publication` auto-detected).
     // This replaces the old `publication_rollup` flow, whose script-node
-    // "aggregations" never ran (the automation engine has no aggregate node) —
-    // and a hook can't do it either (nested cross-object write is unsupported in
-    // the standalone QuickJS runtime; see content/src/hooks/index.ts).
+    // "aggregations" never ran (the automation engine has no aggregate node). A
+    // hook could do it now (nested cross-object writes are safe since
+    // framework#1867), but a `summary` field is the delete-safe, declarative fit
+    // for a pure aggregate; see content/src/hooks/index.ts.
     total_views: Field.summary({
       label: 'Views',
       group: 'rollups',