feat(pipeline): keep Ofsted's graded, ungraded and report-card dates apart

int_ofsted_latest needs to know which inspection came last. Report-card-only schools are no longer dropped (123 schools, audit H3); inspection_date stays for current readers and now falls back to the report-card date, so fact_ofsted_inspection's not_null test still holds.

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

pipeline/transform/models/staging/stg_ofsted_inspections.sql

@@ -1,5 +1,10 @@
 -- Staging model: Ofsted inspection records
--- Handles both OEIF (pre-Nov 2025) and Report Card (post-Nov 2025) frameworks
+-- Handles both OEIF (pre-Nov 2025) and Report Card (post-Nov 2025) frameworks.
+--
+-- Ofsted's MI carries up to three inspections per school: the latest graded
+-- one, the latest ungraded one and the latest report card. Their dates stay
+-- separate here so int_ofsted_latest can tell which came last and which one a
+-- grade belongs to (docs/superpowers/specs/2026-10-05-ofsted-current-status-design.md).
 
 with source as (
     select * from {{ source('raw', 'ofsted_inspections') }}
@@ -8,17 +13,12 @@ with source as (
 renamed as (
     select
         cast(urn as integer)                                                    as urn,
-        -- Inspection event date: the graded inspection when present, otherwise the
-        -- ungraded (Section 8) inspection so schools with only an ungraded
-        -- inspection are still retained.
-        coalesce(
-            to_date(nullif(trim(inspection_date), 'NULL'), 'DD/MM/YYYY'),
-            to_date(nullif(trim(ungraded_inspection_date), 'NULL'), 'DD/MM/YYYY')
-        )                                                                       as inspection_date,
+        to_date(nullif(trim(inspection_date), 'NULL'), 'DD/MM/YYYY')            as graded_inspection_date,
+        to_date(nullif(trim(ungraded_inspection_date), 'NULL'), 'DD/MM/YYYY')   as ungraded_inspection_date,
         inspection_type,
         event_type_grouping                                                     as framework,
 
-        -- OEIF grades (1-4 scale)
+        -- OEIF grades (1-4 scale; 9 = not applicable)
         {{ safe_numeric('overall_effectiveness') }}::integer                    as overall_effectiveness,
         {{ safe_numeric('quality_of_education') }}::integer                     as quality_of_education,
         {{ safe_numeric('behaviour_and_attitudes') }}::integer                  as behaviour_attitudes,
@@ -27,9 +27,9 @@ renamed as (
         {{ safe_numeric('early_years_provision') }}::integer                    as early_years_provision,
         {{ safe_numeric('sixth_form_provision') }}::integer                     as sixth_form_provision,
 
-        -- Ungraded (Section 8) inspection outcome — free text, plus a grade
-        -- parsed from it (1/2/null) used as a last-resort fallback for schools
-        -- with no graded overall effectiveness.
+        -- Ungraded (Section 8) inspection outcome — free text, plus the grade
+        -- it confirms ("School remains Good" → 2); null for outcomes that
+        -- name no grade.
         nullif(trim(ungraded_outcome), 'NULL')                                  as ungraded_outcome,
         {{ parse_ungraded_outcome('ungraded_outcome') }}::integer               as ungraded_grade,
 
@@ -50,31 +50,36 @@ renamed as (
         {{ parse_report_card_grade('rc_sixth_form') }}::integer           as rc_sixth_form,
 
         -- Start date of the latest FULL inspection (the report-card
-        -- inspection in the renewed framework). Guarded in the final select:
-        -- only kept when the row actually carries report-card grades, because
-        -- in legacy-format files this column is the legacy inspection date.
+        -- inspection in the renewed framework). Only kept when the row
+        -- carries report-card grades, because in legacy-format files this
+        -- column is the legacy inspection date.
         to_date(nullif(trim(rc_inspection_date), 'NULL'), 'DD/MM/YYYY')   as rc_inspection_date_raw,
 
         nullif(trim(report_url), 'NULL')                                  as report_url
     from source
     where urn is not null
-      and (
-          nullif(trim(inspection_date), 'NULL') is not null
-          or nullif(trim(ungraded_inspection_date), 'NULL') is not null
-      )
+),
+
+dated as (
+    select
+        *,
+        case
+            when rc_safeguarding_met is not null
+              or rc_inclusion is not null
+              or rc_curriculum_teaching is not null
+              or rc_achievement is not null
+              or rc_attendance_behaviour is not null
+              or rc_personal_development is not null
+              or rc_leadership_governance is not null
+            then rc_inspection_date_raw
+        end as rc_inspection_date
+    from renamed
 )
 
 select
     *,
-    case
-        when rc_safeguarding_met is not null
-          or rc_inclusion is not null
-          or rc_curriculum_teaching is not null
-          or rc_achievement is not null
-          or rc_attendance_behaviour is not null
-          or rc_personal_development is not null
-          or rc_leadership_governance is not null
-        then rc_inspection_date_raw
-    end as rc_inspection_date
-from renamed
-where inspection_date is not null
+    -- For readers that predate the separate dates (fact_ofsted_inspection and
+    -- the backend until it reads fact_ofsted_latest). Never null below.
+    coalesce(graded_inspection_date, ungraded_inspection_date, rc_inspection_date) as inspection_date
+from dated
+where coalesce(graded_inspection_date, ungraded_inspection_date, rc_inspection_date) is not null

pipeline/transform/models/staging/stg_ofsted_inspections.yml

@@ -0,0 +1,25 @@
+version: 2
+
+unit_tests:
+  - name: stg_ofsted_keeps_the_three_dates_apart
+    description: The graded and ungraded dates must stay separate so the latest visit can be found.
+    model: stg_ofsted_inspections
+    given:
+      - input: source('raw', 'ofsted_inspections')
+        rows:
+          - {urn: 102408, inspection_date: '17/06/2025', ungraded_inspection_date: '06/02/2020', overall_effectiveness: 'Not judged', ungraded_outcome: 'School remains Good', rc_inspection_date: '17/06/2025', rc_inclusion: 'NULL'}
+    expect:
+      rows:
+        - {urn: 102408, graded_inspection_date: '2025-06-17', ungraded_inspection_date: '2020-02-06', rc_inspection_date: null, inspection_date: '2025-06-17', ungraded_grade: 2}
+
+  - name: stg_ofsted_keeps_report_card_only_rows
+    description: A school whose only inspection is a report card used to be dropped (audit H3).
+    model: stg_ofsted_inspections
+    given:
+      - input: source('raw', 'ofsted_inspections')
+        rows:
+          - {urn: 149612, inspection_date: 'NULL', ungraded_inspection_date: 'NULL', rc_inspection_date: '10/02/2026', rc_inclusion: 'Expected standard', rc_safeguarding_met: 'Met'}
+          - {urn: 1, inspection_date: 'NULL', ungraded_inspection_date: 'NULL', rc_inspection_date: 'NULL'}
+    expect:
+      rows:
+        - {urn: 149612, graded_inspection_date: null, ungraded_inspection_date: null, rc_inspection_date: '2026-02-10', inspection_date: '2026-02-10', rc_inclusion: 3}