feat(seo): rewrite the C1 snippets to earn the click (W8)

The baseline says these pages already rank and are not clicked. 'compare
school performance' sits at position 6.1 with 0.43% CTR; 'compare schools' at
7.2 with 0.87%. The brand query 'school compare' draws 9.16% from the same
neighbourhood of the same results page, which rules out a ranking explanation
— when the snippet gives a reason to click, it gets clicked.

These SERPs are owned by the DfE's own 'Compare school performance' service.
The old title put a lowercase brand nobody searches for in the most valuable
pixels, then a near-paraphrase of that service's name. Beside the government's
own result it read as a lookalike.

Intent in the title, differentiator in the description. Titles now match what
people type, and the descriptions carry the one fact gov.uk does not publish:
how close you had to live to get a place.

/compare deliberately takes the tool phrasing rather than the homepage's, so
the two pages stop competing for one phrase. The root layout's default and
Open Graph copy were saying something different again; they now agree.

No hard school counts in any of it. The corpus moves with every data refresh
and this repo has already shipped one copy bug of that kind.

Tests guard the mechanics — SERP length, intent keyword, the differentiator,
no brand-first title — and leave the wording free to iterate.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015mWQnpye9F299NVRCCSRvj

nextjs-app/app/compare/page.tsx

@@ -30,9 +30,12 @@ export async function generateMetadata(
   const { urns } = await searchParams;
 
   const base: Metadata = {
-    title: 'Compare Schools',
+    // Deliberately not the homepage's phrase. Two pages chasing "compare
+    // schools" is how a site competes with itself; this one takes the tool
+    // phrasing instead.
+    title: 'School Comparison Tool — Up to Five at Once | schoolcompare',
     description:
-      'Compare schools in England side by side — Ofsted inspections, KS2 and GCSE results against the England average, admissions odds and school community.',
+      'Put up to five English schools in one table: SATs and GCSE results against the England average, Ofsted grades, and the distance places were offered.',
     keywords:
       'school comparison, compare schools, Ofsted comparison, school admissions, KS2 comparison, primary school performance',
     alternates: { canonical: absoluteUrl('/compare') },