fix(rankings,admissions): correct accuracy issues from education audit

Follow-up audit of the rankings and admissions pages.

Admissions (AdmissionsView.tsx):
- National Offer Day no longer claims offers publish "from 12:01 am";
  release times are set per-council (often late afternoon, some
  overnight), so it now tells parents to check their council's page.
- Secondary preference count no longer states a flat "up to six"
  (that's London/Pan-London); most LAs allow three to six. Mirrors the
  hedge the primary step already used.
- Added the two deadlines that most often catch parents out: selective
  schools' separate entrance-test registration (months earlier), and
  faith schools' supplementary information form sent direct to the
  school. Covered in both the primary and secondary criteria steps.
- Reworded the equal-preference tip so it's precise: order is the
  tie-break among schools you qualify for (you get the highest-ranked
  one), not irrelevant.

Rankings (RankingsView.tsx):
- Subtitle "Top-performing schools by X" -> "Schools ranked by X", so
  it isn't nonsensical for context/equity/absence metrics.
- KS2 progress isn't published for 2023/24 or 2024/25 (no KS1
  baseline). Selecting a primary progress metric on a recent year used
  to dead-end on a generic "No rankings found". Added a scoped caveat
  to the progress hint and an explanatory empty-state (primary only —
  secondary Progress 8 is published).

Added an admissions smoke journey (static content, stable milestones).
Verified with tsc --noEmit and next build.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0146VHeLAWjDVE2B5uU67jCB

nextjs-app/components/RankingsView.tsx

@@ -118,7 +118,7 @@ export function RankingsView({
       <header className={styles.header}>
         <h1>School Rankings</h1>
         <p className={styles.subtitle}>
-          Top-performing schools by {metricLabel.toLowerCase()}
+          Schools ranked by {metricLabel.toLowerCase()}
           {!selectedArea && rankings.length > 0 && <span className={styles.limitNote}> — showing top {rankings.length}</span>}
         </p>
       </header>
@@ -143,7 +143,10 @@ export function RankingsView({
         <p className={styles.metricDescription}>{currentMetricDef.description}</p>
       )}
       {isProgressScore && (
-        <p className={styles.progressHint}>Progress scores: 0 = national average. Positive = above average.</p>
+        <p className={styles.progressHint}>
+          Progress scores: 0 = national average. Positive = above average.
+          {isPrimary && ' KS2 progress isn’t published for 2023/24 or 2024/25 (there’s no key stage 1 baseline) — pick an earlier year to rank by it.'}
+        </p>
       )}
 
       {/* Filters */}
@@ -218,7 +221,11 @@ export function RankingsView({
         {rankings.length === 0 ? (
           <EmptyState
             title="No rankings found"
-            message="Try selecting a different metric, area, or year."
+            message={
+              isPrimary && isProgressScore
+                ? 'KS2 progress scores aren’t published for the most recent years (2023/24 and 2024/25) because there’s no key stage 1 baseline. Select an earlier year to see progress rankings.'
+                : 'Try selecting a different metric, area, or year.'
+            }
             action={{
               label: 'Clear filters',
               onClick: () => router.push(`${pathname}?phase=${selectedPhase}`),