chore: remove the Ofsted Parent View feature end to end

Removes the 'What Parents Say' section and all supporting elements:

Frontend:
- Drop the OfstedParentView type, the parent_view field, the survey
  section and the 'X% would recommend' callouts in the primary and
  secondary detail views, the Parents nav item, and the parent-view CSS.

Backend:
- Remove the FactParentView model, its loading in data_loader, and
  parent_view from the school-details API response.
- Bump SCHEMA_VERSION to 6 and add an idempotent drop step
  (DROP TABLE IF EXISTS marts.fact_parent_view) to the CLI migration;
  add scripts/sql/drop_fact_parent_view.sql to apply directly to the
  dbt-owned marts DBs on staging and prod.

Pipeline:
- Delete the stg_parent_view + fact_parent_view dbt models and their
  source/schema entries, the tap-uk-parent-view Meltano extractor, and
  the monthly Parent View DAG; drop it from the Dockerfile and the
  staging bootstrap docs.

The rest of dbt (which builds every mart the app reads) is untouched.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

nextjs-app/app/school/[slug]/page.tsx

@@ -133,7 +133,7 @@ export default async function SchoolPage({ params }: SchoolPageProps) {
     notFound();
   }
 
-  const { school_info, yearly_data, absence_data, ofsted, parent_view, census, admissions, admissions_history, sen_detail, phonics, deprivation, finance } = data;
+  const { school_info, yearly_data, absence_data, ofsted, census, admissions, admissions_history, sen_detail, phonics, deprivation, finance } = data;
 
   // Redirect bare URN to canonical slug URL
   const canonicalSlug = schoolUrl(urn, school_info.school_name).replace('/school/', '');
@@ -189,7 +189,6 @@ export default async function SchoolPage({ params }: SchoolPageProps) {
           yearlyData={yearly_data}
           absenceData={absence_data}
           ofsted={ofsted ?? null}
-          parentView={parent_view ?? null}
           census={census ?? null}
           admissions={admissions ?? null}
           senDetail={sen_detail ?? null}
@@ -203,7 +202,6 @@ export default async function SchoolPage({ params }: SchoolPageProps) {
           yearlyData={yearly_data}
           absenceData={absence_data}
           ofsted={ofsted ?? null}
-          parentView={parent_view ?? null}
           census={census ?? null}
           admissions={admissions ?? null}
           admissionsHistory={admissions_history ?? []}