feat(ofsted): add Report Card system support alongside legacy OEIF grades

Ofsted replaced single overall grades with Report Cards from Nov 2025.
Both systems are retained during the transition period.

- DB: new framework + 9 RC columns on ofsted_inspections (schema v4)
- Integrator: auto-detect OEIF vs Report Card from CSV column headers;
  parse 5-level RC grades and safeguarding met/not-met
- API: expose all new fields in the ofsted response dict
- Frontend: branch on framework='ReportCard' to show safeguarding badge
  + 8-category grid; fall back to legacy OEIF layout otherwise;
  always show inspection date in both layouts
- CSS: rcGrade1–5 and safeguardingMet/NotMet classes

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

backend/version.py

@@ -13,11 +13,12 @@ WHEN TO BUMP:
 """
 
 # Current schema version - increment when models change
-SCHEMA_VERSION = 3
+SCHEMA_VERSION = 4
 
 # Changelog for documentation
 SCHEMA_CHANGELOG = {
     1: "Initial schema with School and SchoolResult tables",
     2: "Added pupil absence fields (reading, maths, gps, writing, science)",
     3: "Added supplementary data tables: ofsted, parent_view, census, admissions, sen_detail, phonics, deprivation, finance; GIAS columns on schools",
+    4: "Added Ofsted Report Card columns to ofsted_inspections (new framework from Nov 2025)",
 }