diff --git a/lib/database.types.ts b/lib/database.types.ts
index fa6d7cd..d966295 100644
--- a/lib/database.types.ts
+++ b/lib/database.types.ts
@@ -72,6 +72,13 @@ export type Database = {
           user_id?: string
         }
         Relationships: [
+          {
+            foreignKeyName: "engagement_sessions_post_id_fkey"
+            columns: ["post_id"]
+            isOneToOne: false
+            referencedRelation: "post_engagement_metrics"
+            referencedColumns: ["post_id"]
+          },
           {
             foreignKeyName: "engagement_sessions_post_id_fkey"
             columns: ["post_id"]
@@ -146,6 +153,13 @@ export type Database = {
           updated_at?: string
         }
         Relationships: [
+          {
+            foreignKeyName: "post_comments_post_id_fkey"
+            columns: ["post_id"]
+            isOneToOne: false
+            referencedRelation: "post_engagement_metrics"
+            referencedColumns: ["post_id"]
+          },
           {
             foreignKeyName: "post_comments_post_id_fkey"
             columns: ["post_id"]
@@ -178,6 +192,13 @@ export type Database = {
           user_id?: string
         }
         Relationships: [
+          {
+            foreignKeyName: "post_ratings_post_id_fkey"
+            columns: ["post_id"]
+            isOneToOne: false
+            referencedRelation: "post_engagement_metrics"
+            referencedColumns: ["post_id"]
+          },
           {
             foreignKeyName: "post_ratings_post_id_fkey"
             columns: ["post_id"]
@@ -210,6 +231,13 @@ export type Database = {
           user_id?: string
         }
         Relationships: [
+          {
+            foreignKeyName: "post_reactions_post_id_fkey"
+            columns: ["post_id"]
+            isOneToOne: false
+            referencedRelation: "post_engagement_metrics"
+            referencedColumns: ["post_id"]
+          },
           {
             foreignKeyName: "post_reactions_post_id_fkey"
             columns: ["post_id"]
@@ -389,6 +417,22 @@ export type Database = {
       }
     }
     Views: {
+      post_engagement_daily: {
+        Row: {
+          avg_rating: number | null
+          avg_scroll: number | null
+          avg_seconds: number | null
+          click_rate: number | null
+          day: string | null
+          post_id: string | null
+          total_comments: number | null
+          total_ratings: number | null
+          total_reactions: number | null
+          unique_clicks: number | null
+          unique_readers: number | null
+        }
+        Relationships: []
+      }
       post_engagement_metrics: {
         Row: {
           avg_rating: number | null
diff --git a/supabase/migrations/20260711000001_create_post_engagement_daily_mv.sql b/supabase/migrations/20260711000001_create_post_engagement_daily_mv.sql
new file mode 100644
index 0000000..fe9defd
--- /dev/null
+++ b/supabase/migrations/20260711000001_create_post_engagement_daily_mv.sql
@@ -0,0 +1,157 @@
+-- Migration: vista materializada post_engagement_daily + refresco horario (pg_cron)
+-- Part of Epic N04 / Feature F-N04-03 (#175) / Issue I-F-N04-03-02 (#181)
+-- refs: docs/adr/0001-engagement.md · docs/adr/0006-engagement-behavioral-signals.md
+--       métricas de origen: 20260711000000_create_post_engagement_metrics_view.sql (#180)
+--
+-- Materializa las métricas por (post_id, día) para que el dashboard no ataque
+-- engagement_sessions cruda. Lag máximo del dashboard: 1 hora (refresco horario).
+--
+-- ── Por qué la MV vive en el schema `private` ────────────────────────────────
+-- Las vistas materializadas NO soportan RLS ni `security_invoker`. Si se expusiera
+-- con grant a `authenticated`, cualquier staff podría leer el engagement de todos
+-- los posts. `private` no está en `[api] schemas` (config.toml), así que PostgREST
+-- no lo expone. El acceso pasa por la vista pública `public.post_engagement_daily`,
+-- que corre con permisos del owner y filtra con el guard `is_manager()`.
+--
+-- ── Fan-out ──────────────────────────────────────────────────────────────────
+-- Cada fuente se pre-agrega por (post_id, día) y luego se une sobre un "spine" con
+-- todos los pares (post_id, día) presentes en cualquier fuente. Unir las tablas
+-- directamente multiplicaría los conteos (producto cartesiano).
+--
+-- ── Días en UTC ──────────────────────────────────────────────────────────────
+-- `at time zone 'utc'` hace el bucketing determinista e independiente del TimeZone
+-- de la sesión que consulte o refresque.
+
+create schema if not exists private;
+
+revoke all on schema private from public;
+revoke all on schema private from anon, authenticated;
+
+create materialized view private.post_engagement_daily as
+with sessions as (
+  select
+    post_id,
+    (started_at at time zone 'utc')::date               as day,
+    count(distinct user_id)                             as unique_readers,
+    count(distinct user_id) filter (where link_clicked) as unique_clicks,
+    avg(focused_seconds)::numeric(10,2)                 as avg_seconds,
+    avg(max_scroll_pct)::numeric(4,3)                   as avg_scroll
+  from public.engagement_sessions
+  group by post_id, (started_at at time zone 'utc')::date
+),
+ratings as (
+  select
+    post_id,
+    (created_at at time zone 'utc')::date as day,
+    avg(rating)::numeric(3,2)             as avg_rating,
+    count(*)                              as total_ratings
+  from public.post_ratings
+  group by post_id, (created_at at time zone 'utc')::date
+),
+reactions as (
+  select
+    post_id,
+    (created_at at time zone 'utc')::date as day,
+    count(*)                              as total_reactions
+  from public.post_reactions
+  group by post_id, (created_at at time zone 'utc')::date
+),
+comments as (
+  select
+    post_id,
+    (created_at at time zone 'utc')::date as day,
+    count(*)                              as total_comments
+  from public.post_comments
+  group by post_id, (created_at at time zone 'utc')::date
+),
+spine as (
+  select post_id, day from sessions
+  union
+  select post_id, day from ratings
+  union
+  select post_id, day from reactions
+  union
+  select post_id, day from comments
+)
+select
+  sp.post_id,
+  sp.day,
+  coalesce(s.unique_readers, 0)   as unique_readers,
+  coalesce(s.unique_clicks, 0)    as unique_clicks,
+  -- nullif evita la división por cero: sin lectores ese día, el ratio es NULL.
+  round(
+    coalesce(s.unique_clicks, 0)::numeric / nullif(s.unique_readers, 0),
+    4
+  )                               as click_rate,
+  r.avg_rating,
+  coalesce(r.total_ratings, 0)    as total_ratings,
+  coalesce(rx.total_reactions, 0) as total_reactions,
+  coalesce(c.total_comments, 0)   as total_comments,
+  -- Señales opcionales (ADR-0006).
+  s.avg_seconds,
+  s.avg_scroll
+from spine sp
+left join sessions  s  on s.post_id  = sp.post_id and s.day  = sp.day
+left join ratings   r  on r.post_id  = sp.post_id and r.day  = sp.day
+left join reactions rx on rx.post_id = sp.post_id and rx.day = sp.day
+left join comments  c  on c.post_id  = sp.post_id and c.day  = sp.day;
+
+-- Índice único: requisito de REFRESH MATERIALIZED VIEW CONCURRENTLY (refresca sin
+-- bloquear las lecturas del dashboard).
+create unique index post_engagement_daily_pk
+  on private.post_engagement_daily (post_id, day);
+
+create index post_engagement_daily_day_idx
+  on private.post_engagement_daily (day desc);
+
+comment on materialized view private.post_engagement_daily is
+  'Métricas de engagement por (post_id, día). Refresco horario vía pg_cron; lag máximo 1h. '
+  'No expuesta por PostgREST (las MV no soportan RLS): el acceso va por public.post_engagement_daily.';
+
+-- ── Acceso público (RBAC en Postgres) ────────────────────────────────────────
+-- Vista con permisos del owner (lee la MV en `private`) + guard is_manager()
+-- (jerarquía inclusiva: admin > manager). Staff obtiene 0 filas.
+create or replace view public.post_engagement_daily as
+select
+  d.post_id,
+  d.day,
+  d.unique_readers,
+  d.unique_clicks,
+  d.click_rate,
+  d.avg_rating,
+  d.total_ratings,
+  d.total_reactions,
+  d.total_comments,
+  d.avg_seconds,
+  d.avg_scroll
+from private.post_engagement_daily d
+where public.is_manager();
+
+comment on view public.post_engagement_daily is
+  'Lectura del dashboard sobre la MV private.post_engagement_daily (F-N04-03). '
+  'Solo admin/manager (guard is_manager()); staff obtiene 0 filas.';
+
+grant select on public.post_engagement_daily to authenticated;
+
+-- ── Refresco horario ─────────────────────────────────────────────────────────
+create extension if not exists pg_cron;
+
+create or replace function private.refresh_post_engagement_daily()
+returns void
+language sql
+security definer
+set search_path = ''
+as $$
+  refresh materialized view concurrently private.post_engagement_daily;
+$$;
+
+comment on function private.refresh_post_engagement_daily() is
+  'Refresco CONCURRENTLY (no bloquea lecturas). Lo invoca el job horario de pg_cron.';
+
+-- Job idempotente: cron.schedule hace upsert por nombre, así que re-aplicar la
+-- migración no duplica el job. Cada hora en punto → lag máximo de 1h.
+select cron.schedule(
+  'refresh-post-engagement-daily',
+  '0 * * * *',
+  $$ select private.refresh_post_engagement_daily() $$
+);
diff --git a/supabase/tests/rls/mv_post_engagement_daily.sql b/supabase/tests/rls/mv_post_engagement_daily.sql
new file mode 100644
index 0000000..9d3089c
--- /dev/null
+++ b/supabase/tests/rls/mv_post_engagement_daily.sql
@@ -0,0 +1,160 @@
+-- Tests: MV private.post_engagement_daily + vista public.post_engagement_daily
+-- Issue I-F-N04-03-02 (#181) — migración 20260711000001_create_post_engagement_daily_mv
+-- refs: docs/adr/0001-engagement.md · docs/adr/0006-engagement-behavioral-signals.md
+--
+-- Dataset fijo con timestamps UTC explícitos (el bucketing de día es determinista).
+-- Cubre: agregación por (post_id, día) desde las 4 fuentes, ausencia de fan-out,
+-- día sin sesiones (click_rate NULL, sin división por cero), índice único para el
+-- refresh concurrente, job horario de pg_cron y RBAC (staff no ve nada).
+--
+-- Nota: los tests corren en transacción, y REFRESH ... CONCURRENTLY no puede correr
+-- dentro de un bloque transaccional; aquí se usa el REFRESH plano (equivalente en
+-- resultado). El CONCURRENTLY lo ejerce el job de cron fuera de transacción.
+--
+-- Seed UUIDs (supabase/seed.sql) — ids de auth.users:
+--   admin:   aaaaaaaa-0000-0000-0000-000000000001
+--   manager: aaaaaaaa-0000-0000-0000-000000000002
+--   staff:   aaaaaaaa-0000-0000-0000-000000000003
+
+begin;
+select plan(10);
+
+create or replace function pg_temp.set_session(uid uuid)
+returns void language plpgsql as $$
+begin
+  perform set_config(
+    'request.jwt.claims',
+    json_build_object('sub', uid::text, 'role', 'authenticated')::text,
+    true
+  );
+  set local role authenticated;
+end;
+$$;
+
+-- ── Estructura ──────────────────────────────────────────────────────────────
+select ok(
+  (select count(*) from pg_matviews
+    where schemaname = 'private' and matviewname = 'post_engagement_daily') = 1,
+  'existe la MV private.post_engagement_daily (fuera del schema expuesto por PostgREST)'
+);
+
+select ok(
+  exists (
+    select 1
+    from pg_index i
+    join pg_class ic on ic.oid = i.indexrelid
+    join pg_class tc on tc.oid = i.indrelid
+    join pg_namespace n on n.oid = tc.relnamespace
+    where n.nspname = 'private'
+      and tc.relname = 'post_engagement_daily'
+      and ic.relname = 'post_engagement_daily_pk'
+      and i.indisunique
+  ),
+  'índice único (post_id, day): requisito de REFRESH MATERIALIZED VIEW CONCURRENTLY'
+);
+
+select is(
+  (select schedule from cron.job where jobname = 'refresh-post-engagement-daily'),
+  '0 * * * *',
+  'refresco programado cada hora vía pg_cron (lag máximo del dashboard: 1h)'
+);
+
+select has_view('public', 'post_engagement_daily', 'existe la vista pública que consume el dashboard');
+
+-- ── Dataset fijo (como postgres = bypass RLS) ───────────────────────────────
+insert into public.posts (id, author_id, title, external_url, status, published_at)
+select 'aaaaaaaa-4444-0000-0000-00000000000a'::uuid, p.id, 'Daily metrics post',
+       'https://example.com/daily', 'published', '2026-07-01T08:00:00Z'
+from public.profiles p where p.user_id = 'aaaaaaaa-0000-0000-0000-000000000002'::uuid;
+
+-- Día 1 (2026-07-01): 2 lectores, 1 clic. engagement_sessions es 1 fila por
+-- (user_id, post_id), así que cada usuario aporta a un único día por post.
+insert into public.engagement_sessions
+  (user_id, post_id, started_at, link_clicked, status, focused_seconds, max_scroll_pct)
+values
+  ('aaaaaaaa-0000-0000-0000-000000000003'::uuid, 'aaaaaaaa-4444-0000-0000-00000000000a'::uuid,
+   '2026-07-01T10:00:00Z', true,  'clicked', 10, 0.800),
+  ('aaaaaaaa-0000-0000-0000-000000000002'::uuid, 'aaaaaaaa-4444-0000-0000-00000000000a'::uuid,
+   '2026-07-01T11:00:00Z', false, 'viewed',  20, 0.400);
+
+-- Día 1: 2 valoraciones (staff 5, manager 3) y 1 reacción (staff).
+insert into public.post_ratings (post_id, user_id, rating, created_at) values
+  ('aaaaaaaa-4444-0000-0000-00000000000a'::uuid, 'aaaaaaaa-0000-0000-0000-000000000003'::uuid,
+   5, '2026-07-01T12:00:00Z'),
+  ('aaaaaaaa-4444-0000-0000-00000000000a'::uuid, 'aaaaaaaa-0000-0000-0000-000000000002'::uuid,
+   3, '2026-07-01T13:00:00Z');
+
+insert into public.post_reactions (post_id, user_id, type, created_at) values
+  ('aaaaaaaa-4444-0000-0000-00000000000a'::uuid, 'aaaaaaaa-0000-0000-0000-000000000003'::uuid,
+   'like', '2026-07-01T12:30:00Z');
+
+-- Día 2 (2026-07-02): SIN sesiones; solo una valoración del admin.
+-- Ejercita el "spine" (el día existe aunque no haya sesiones) y la división por cero.
+insert into public.post_ratings (post_id, user_id, rating, created_at) values
+  ('aaaaaaaa-4444-0000-0000-00000000000a'::uuid, 'aaaaaaaa-0000-0000-0000-000000000001'::uuid,
+   4, '2026-07-02T09:00:00Z');
+
+refresh materialized view private.post_engagement_daily;
+
+-- ── Métricas del día 1 (como manager) ───────────────────────────────────────
+select pg_temp.set_session('aaaaaaaa-0000-0000-0000-000000000002'::uuid);
+
+select results_eq(
+  $$ select unique_readers, unique_clicks, click_rate
+     from public.post_engagement_daily
+     where post_id = 'aaaaaaaa-4444-0000-0000-00000000000a'::uuid
+       and day = '2026-07-01'::date $$,
+  $$ values (2::bigint, 1::bigint, 0.5000::numeric) $$,
+  'día 1: unique_readers=2, unique_clicks=1, click_rate=0.5'
+);
+
+-- Con 2 sesiones × 2 ratings × 1 reacción, un JOIN sin pre-agregar daría
+-- total_reactions=2 y total_ratings=4. Aquí se comprueba que no hay fan-out.
+select results_eq(
+  $$ select avg_rating, total_ratings, total_reactions, total_comments
+     from public.post_engagement_daily
+     where post_id = 'aaaaaaaa-4444-0000-0000-00000000000a'::uuid
+       and day = '2026-07-01'::date $$,
+  $$ values (4.00::numeric(3,2), 2::bigint, 1::bigint, 0::bigint) $$,
+  'día 1: avg_rating=4.00, ratings=2, reactions=1, comments=0 (sin fan-out)'
+);
+
+select results_eq(
+  $$ select avg_seconds, avg_scroll
+     from public.post_engagement_daily
+     where post_id = 'aaaaaaaa-4444-0000-0000-00000000000a'::uuid
+       and day = '2026-07-01'::date $$,
+  $$ values (15.00::numeric(10,2), 0.600::numeric(4,3)) $$,
+  'día 1: señales opcionales avg_seconds=15.00, avg_scroll=0.600 (ADR-0006)'
+);
+
+-- ── Día 2: sin sesiones → click_rate NULL, sin división por cero ────────────
+select results_eq(
+  $$ select unique_readers, unique_clicks, click_rate, avg_rating, total_ratings
+     from public.post_engagement_daily
+     where post_id = 'aaaaaaaa-4444-0000-0000-00000000000a'::uuid
+       and day = '2026-07-02'::date $$,
+  $$ values (0::bigint, 0::bigint, null::numeric, 4.00::numeric(3,2), 1::bigint) $$,
+  'día 2 sin sesiones: unique_readers=0 y click_rate NULL (sin división por cero)'
+);
+
+select results_eq(
+  $$ select count(*)::int from public.post_engagement_daily
+     where post_id = 'aaaaaaaa-4444-0000-0000-00000000000a'::uuid $$,
+  $$ values (2) $$,
+  'el post agrega en 2 filas: una por día con actividad'
+);
+
+-- ── RBAC ────────────────────────────────────────────────────────────────────
+select pg_temp.set_session('aaaaaaaa-0000-0000-0000-000000000003'::uuid);
+
+select results_eq(
+  $$ select count(*)::int from public.post_engagement_daily $$,
+  $$ values (0) $$,
+  'staff no ve datos del dashboard (vista vacía)'
+);
+
+reset role;
+
+select * from finish();
+rollback;