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>

backend/app.py

@@ -28,8 +28,6 @@ from .data_loader import (
     get_supplementary_data,
 )
 from .data_loader import get_data_info as get_db_info
-from .database import check_and_migrate_if_needed
-from .migration import run_full_migration
 from .schemas import METRIC_DEFINITIONS, RANKING_COLUMNS, SCHOOL_COLUMNS
 from .utils import clean_for_json
 
@@ -138,20 +136,15 @@ def validate_postcode(postcode: Optional[str]) -> Optional[str]:
 @asynccontextmanager
 async def lifespan(app: FastAPI):
     """Application lifespan - startup and shutdown events."""
-    # Startup: check schema version and migrate if needed
-    print("Starting up: Checking database schema...")
-    check_and_migrate_if_needed()
-
-    print("Loading school data from database...")
+    print("Loading school data from marts...")
     df = load_school_data()
     if df.empty:
-        print("Warning: No data in database. Check CSV files in data/ folder.")
+        print("Warning: No data in marts. Run the annual EES pipeline to populate KS2 data.")
     else:
         print(f"Data loaded successfully: {len(df)} records.")
 
-    yield  # Application runs here
+    yield
 
-    # Shutdown: cleanup if needed
     print("Shutting down...")
 
 
@@ -585,7 +578,7 @@ async def get_data_info(request: Request):
     if db_info["total_schools"] == 0:
         return {
             "status": "no_data",
-            "message": "No data in database. Run the migration script: python scripts/migrate_csv_to_db.py",
+            "message": "No data in marts. Run the annual EES pipeline to load KS2 data.",
             "data_source": "PostgreSQL",
         }
 
@@ -635,56 +628,6 @@ async def reload_data(
     return {"status": "reloaded"}
 
 
-_reimport_status: dict = {"running": False, "done": False, "error": None}
-
-
-@app.post("/api/admin/reimport-ks2")
-@limiter.limit("2/minute")
-async def reimport_ks2(
-    request: Request,
-    geocode: bool = True,
-    _: bool = Depends(verify_admin_api_key)
-):
-    """
-    Start a full KS2 CSV migration in the background and return immediately.
-    Poll GET /api/admin/reimport-ks2/status to check progress.
-    Pass ?geocode=false to skip postcode → lat/lng resolution.
-    Requires X-API-Key header with valid admin API key.
-    """
-    global _reimport_status
-    if _reimport_status["running"]:
-        return {"status": "already_running"}
-
-    _reimport_status = {"running": True, "done": False, "error": None}
-
-    def _run():
-        global _reimport_status
-        try:
-            success = run_full_migration(geocode=geocode)
-            if not success:
-                _reimport_status = {"running": False, "done": False, "error": "No CSV data found"}
-                return
-            clear_cache()
-            load_school_data()
-            _reimport_status = {"running": False, "done": True, "error": None}
-        except Exception as exc:
-            _reimport_status = {"running": False, "done": False, "error": str(exc)}
-
-    import threading
-    threading.Thread(target=_run, daemon=True).start()
-    return {"status": "started"}
-
-
-@app.get("/api/admin/reimport-ks2/status")
-async def reimport_ks2_status(
-    request: Request,
-    _: bool = Depends(verify_admin_api_key)
-):
-    """Poll this endpoint to check reimport progress."""
-    s = _reimport_status
-    if s["error"]:
-        raise HTTPException(status_code=500, detail=s["error"])
-    return {"running": s["running"], "done": s["done"]}
 
 
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