feat: migrate backend to marts schema, update EES tap for verified datasets

Pipeline:
- EES tap: split KS4 into performance + info streams, fix admissions filename
  (SchoolLevel keyword match), fix census filename (yearly suffix), remove
  phonics (no school-level data on EES), change endswith → in for matching
- stg_ees_ks4: rewrite to filter long-format data and extract Attainment 8,
  Progress 8, EBacc, English/Maths metrics; join KS4 info for context
- stg_ees_admissions: map real CSV columns (total_number_places_offered, etc.)
- stg_ees_census: update source reference, stub with TODO for data columns
- Remove stg_ees_phonics, fact_phonics (no school-level EES data)
- Add ees_ks4_performance + ees_ks4_info sources, remove ees_ks4 + ees_phonics
- Update int_ks4_with_lineage + fact_ks4_performance with new KS4 columns
- Annual EES DAG: remove stg_ees_phonics+ from selector

Backend:
- models.py: replace all models to point at marts.* tables with schema='marts'
  (DimSchool, DimLocation, KS2Performance, FactOfstedInspection, etc.)
- data_loader.py: rewrite load_school_data_as_dataframe() using raw SQL joining
  dim_school + dim_location + fact_ks2_performance; update get_supplementary_data()
- database.py: remove migration machinery, keep only connection setup
- app.py: remove check_and_migrate_if_needed, remove /api/admin/reimport-ks2
  endpoints (pipeline handles all imports)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pipeline/transform/models/marts/_marts_schema.yml

@@ -88,14 +88,6 @@ models:
       - name: year
         tests: [not_null]
 
-  - name: fact_phonics
-    description: Phonics screening results — one row per URN per year
-    columns:
-      - name: urn
-        tests: [not_null]
-      - name: year
-        tests: [not_null]
-
   - name: fact_parent_view
     description: Parent View survey responses
     columns:

pipeline/transform/models/marts/fact_admissions.sql

@@ -3,8 +3,12 @@
 select
     urn,
     year,
+    school_phase,
     published_admission_number,
     total_applications,
-    first_preference_offers_pct,
-    oversubscribed
+    first_preference_applications,
+    first_preference_offers,
+    first_preference_offer_pct,
+    oversubscribed,
+    admissions_policy
 from {{ ref('stg_ees_admissions') }}

pipeline/transform/models/marts/fact_ks4_performance.sql

@@ -1,16 +1,42 @@
 -- Mart: KS4 performance fact table — one row per URN per year
+-- Includes predecessor data via lineage resolution
 
 select
     current_urn as urn,
     source_urn,
     year,
     total_pupils,
-    progress_8_score,
+    eligible_pupils,
+    prior_attainment_avg,
+
+    -- Attainment 8
     attainment_8_score,
-    ebacc_entry_pct,
-    ebacc_achievement_pct,
-    english_strong_pass_pct,
-    maths_strong_pass_pct,
+
+    -- Progress 8
+    progress_8_score,
+    progress_8_lower_ci,
+    progress_8_upper_ci,
+    progress_8_english,
+    progress_8_maths,
+    progress_8_ebacc,
+    progress_8_open,
+
+    -- English & Maths
     english_maths_strong_pass_pct,
-    staying_in_education_pct
+    english_maths_standard_pass_pct,
+
+    -- EBacc
+    ebacc_entry_pct,
+    ebacc_strong_pass_pct,
+    ebacc_standard_pass_pct,
+    ebacc_avg_score,
+
+    -- GCSE
+    gcse_grade_91_pct,
+
+    -- Context
+    sen_pct,
+    sen_ehcp_pct,
+    sen_support_pct
+
 from {{ ref('int_ks4_with_lineage') }}

pipeline/transform/models/marts/fact_phonics.sql

@@ -1,8 +0,0 @@
--- Mart: Phonics screening results — one row per URN per year
-
-select
-    urn,
-    year,
-    year1_phonics_pct,
-    year2_phonics_pct
-from {{ ref('stg_ees_phonics') }}

pipeline/transform/models/marts/fact_pupil_characteristics.sql

@@ -1,18 +1,8 @@
 -- Mart: Pupil characteristics — one row per URN per year
+-- TODO: Expand once census data columns are verified and added to staging
 
 select
     urn,
     year,
-    fsm_pct,
-    sen_support_pct,
-    sen_ehcp_pct,
-    eal_pct,
-    disadvantaged_pct,
-    ethnicity_white_pct,
-    ethnicity_asian_pct,
-    ethnicity_black_pct,
-    ethnicity_mixed_pct,
-    ethnicity_other_pct,
-    class_size_avg,
-    stability_pct
+    phase_type_grouping
 from {{ ref('int_pupil_chars_merged') }}