feat: notify tenants about public bank syncs

supabase/migrations/202606290017_tenant_content_notifications.sql

@@ -0,0 +1,50 @@
+create table if not exists public.tenant_content_notifications (
+  id uuid primary key default gen_random_uuid(),
+  tenant_id uuid not null references public.tenants(id) on delete cascade,
+  notification_type text not null
+    check (notification_type in (
+      'public_question_bank_synced',
+      'public_question_bank_conflict'
+    )),
+  status text not null default 'unread'
+    check (status in ('unread', 'read', 'dismissed', 'resolved')),
+  severity text not null default 'info'
+    check (severity in ('info', 'success', 'warning', 'error')),
+  adoption_id uuid references public.tenant_question_bank_adoptions(id) on delete cascade,
+  source_question_bank_id uuid references public.question_banks(id) on delete cascade,
+  title text not null,
+  message text not null,
+  action_label text,
+  action_path text,
+  dedupe_key text,
+  metadata jsonb not null default '{}'::jsonb,
+  created_by uuid references public.platform_users(id) on delete set null,
+  read_by uuid references public.platform_users(id) on delete set null,
+  read_at timestamptz,
+  resolved_at timestamptz,
+  created_at timestamptz not null default now(),
+  updated_at timestamptz not null default now()
+);
+
+create unique index if not exists idx_tenant_content_notifications_dedupe
+  on public.tenant_content_notifications(tenant_id, notification_type, dedupe_key)
+  where dedupe_key is not null;
+
+create index if not exists idx_tenant_content_notifications_tenant_status
+  on public.tenant_content_notifications(tenant_id, status, created_at desc);
+
+create index if not exists idx_tenant_content_notifications_adoption
+  on public.tenant_content_notifications(tenant_id, adoption_id, notification_type, status);
+
+alter table public.tenant_content_notifications enable row level security;
+
+drop policy if exists tenant_content_notifications_isolation on public.tenant_content_notifications;
+create policy tenant_content_notifications_isolation on public.tenant_content_notifications
+  for all
+  using (tenant_id = app.current_tenant_id() or app.is_platform_admin())
+  with check (tenant_id = app.current_tenant_id() or app.is_platform_admin());
+
+drop trigger if exists set_updated_at on public.tenant_content_notifications;
+create trigger set_updated_at
+  before update on public.tenant_content_notifications
+  for each row execute function app.touch_updated_at();