Publish which blood-pressure axis set the pillar score

The score is the worse of the systolic and diastolic sub-scores, and
until now nothing said which one it was or how far over its ceiling the
reading sat. The grader now returns that basis together with the score,
as one value, and it is carried as one value all the way to the pillar
so an explanation can never belong to a different grading run than the
number it explains.

src/app/api/analytics/route.ts

@@ -360,6 +360,17 @@ async function buildAnalyticsResponse(user: AuthedUser, locale: Locale) {
         }),
       ],
     );
+    // The pillar is graded against the CLINICAL band even when the user
+    // keeps a personal target (that band is the number's identity; the
+    // personal one is displayed beside it and scores nothing). So when the
+    // two differ we re-run the whole helper against the clinical targets
+    // and the score comes from that second run.
+    //
+    // v1.34.5 — the "why this number" basis rides the same envelope, so it
+    // is the same run, the same representative pair and the same ceilings
+    // by construction. Assign envelopes WHOLE here; picking `graded.score`
+    // off one run and a basis off the other would let the popover explain
+    // a number nobody is looking at, and it would look correct in review.
     if (bpTargetsEqual(bpTargets, clinicalBpTargets)) {
       bpEnvelope = windows;
       bpEnvelopePriorWeek = windowsPriorWeek;