chore(insights): remove the "Try a 7-day experiment" placeholder

Every correlation card carried a permanently disabled button with the
tooltip "Coming soon", which on a phone (no hover) was just a dead
control. The feature it stood for was never built; the button and its
two strings go in all ten locales. The Coach hand-off and the dismiss
action stay.

messages/de.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "Zusammenhänge",
-      "experimentCta": "7-Tage-Experiment starten",
-      "experimentTooltip": "Bald verfügbar",
       "emptyTitle": "Mehr Daten nötig, um diesen Zusammenhang zu zeigen",
       "sourceChip": "basierend auf {n} gepaarten Messungen ({window})",
       "sourceWindowLast30": "letzte 30 Tage",

messages/en.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "Relationships",
-      "experimentCta": "Try a 7-day experiment",
-      "experimentTooltip": "Coming soon",
       "emptyTitle": "Need more data to see this relationship",
       "sourceChip": "based on {n} paired readings ({window})",
       "sourceWindowLast30": "last 30 days",

messages/es.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "Correlaciones",
-      "experimentCta": "Iniciar experimento de 7 días",
-      "experimentTooltip": "Próximamente",
       "emptyTitle": "Necesitamos más datos para mostrar esta correlación",
       "sourceChip": "basado en {n} mediciones pareadas ({window})",
       "sourceWindowLast30": "Últimos 30 días",

messages/fr.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "Corrélations",
-      "experimentCta": "Lancer une expérience de 7 jours",
-      "experimentTooltip": "Bientôt disponible",
       "emptyTitle": "Il faut plus de données pour afficher cette corrélation",
       "sourceChip": "sur la base de {n} mesures appariées ({window})",
       "sourceWindowLast30": "30 derniers jours",

messages/it.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "Correlazioni",
-      "experimentCta": "Avvia esperimento di 7 giorni",
-      "experimentTooltip": "In arrivo",
       "emptyTitle": "Servono più dati per mostrare questa correlazione",
       "sourceChip": "su {n} misurazioni appaiate ({window})",
       "sourceWindowLast30": "Ultimi 30 giorni",

messages/ko.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "관계",
-      "experimentCta": "7일 실험 해보기",
-      "experimentTooltip": "곧 제공돼요",
       "emptyTitle": "이 관계를 보려면 데이터가 더 필요해요",
       "sourceChip": "짝지은 측정값 {n}개 기준 ({window})",
       "sourceWindowLast30": "최근 30일",

messages/nl.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "Verbanden",
-      "experimentCta": "Probeer een experiment van 7 dagen",
-      "experimentTooltip": "Binnenkort beschikbaar",
       "emptyTitle": "Meer gegevens nodig om dit verband te zien",
       "sourceChip": "gebaseerd op {n} gekoppelde metingen ({window})",
       "sourceWindowLast30": "afgelopen 30 dagen",

messages/pl.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "Korelacje",
-      "experimentCta": "Uruchom 7-dniowy eksperyment",
-      "experimentTooltip": "Wkrótce",
       "emptyTitle": "Potrzeba więcej danych, aby pokazać tę korelację",
       "sourceChip": "na podstawie {n} sparowanych pomiarów ({window})",
       "sourceWindowLast30": "Ostatnie 30 dni",

messages/pt-BR.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "Relações",
-      "experimentCta": "Tente um experimento de 7 dias",
-      "experimentTooltip": "Em breve",
       "emptyTitle": "Precisa de mais dados para ver esta relação",
       "sourceChip": "com base em {n} leituras pareadas ({window})",
       "sourceWindowLast30": "últimos 30 dias",

messages/ru.json

@@ -3017,8 +3017,6 @@
     },
     "correlationRow": {
       "title": "Связи",
-      "experimentCta": "Попробовать 7-дневный эксперимент",
-      "experimentTooltip": "Скоро",
       "emptyTitle": "Нужно больше данных, чтобы увидеть эту связь",
       "sourceChip": "на основе {n} парных измерений ({window})",
       "sourceWindowLast30": "последние 30 дней",

src/components/insights/__tests__/correlation-card.test.tsx

@@ -81,18 +81,15 @@ describe("<CorrelationCard>", () => {
     expect(html).toContain("High confidence");
   });
 
-  it("renders the disabled experiment CTA with the Coming-soon tooltip", () => {
+  it("offers no placeholder action, only ones that work", () => {
     const html = render(<CorrelationCard result={okResult} />);
-    expect(html).toMatch(/data-slot="correlation-card-cta"/);
-    expect(html).toContain("Try a 7-day experiment");
-    expect(html).toMatch(/disabled/);
-    expect(html).toContain("Coming soon");
+    expect(html).not.toMatch(/data-slot="correlation-card-cta"/);
+    expect(html).not.toMatch(/<button[^>]*disabled/);
   });
 
   it("renders the empty-state when status=insufficient", () => {
     const html = render(<CorrelationCard result={insufficient} />);
     expect(html).toContain("Need more data to see this relationship");
-    expect(html).not.toContain("Try a 7-day experiment");
   });
 
   it("tags the wrapper with the correlation kind", () => {
@@ -103,7 +100,7 @@ describe("<CorrelationCard>", () => {
   it("renders German copy when locale=de", () => {
     const html = render(<CorrelationCard result={okResult} />, "de");
     expect(html).toContain("BD × Therapietreue");
-    expect(html).toContain("7-Tage-Experiment");
+    expect(html).toContain("basierend auf 28 gepaarten Messungen");
   });
 
   it("never surfaces causal language in the interpretation slot", () => {

src/components/insights/correlation-card.tsx

@@ -1,8 +1,7 @@
 "use client";
 
 import dynamic from "next/dynamic";
-import { Activity, Sparkles } from "lucide-react";
-import { Button } from "@/components/ui/button";
+import { Activity } from "lucide-react";
 import { Card, CardContent, CardHeader } from "@/components/ui/card";
 import { TileHeader } from "@/components/insights/tile-header";
 import { EmptyState } from "@/components/ui/empty-state";
@@ -177,27 +176,7 @@ export function CorrelationCard({ result }: CorrelationCardProps) {
               })}
             </p>
             <div className="flex flex-wrap items-center gap-2">
-              <Button
-                type="button"
-                size="sm"
-                // Outline variant so the disabled placeholder reads as
-                // "this is on the roadmap" rather than "the system is
-                // broken right now". Flip back to default when the
-                // 7-day experiment feature ships in v1.5.
-                variant="outline"
-                disabled
-                data-slot="correlation-card-cta"
-                className="gap-1.5"
-                title={t("insights.correlationRow.experimentTooltip")}
-              >
-                <Sparkles className="h-3.5 w-3.5" aria-hidden="true" />
-                <span>{t("insights.correlationRow.experimentCta")}</span>
-                <span className="sr-only">
-                  , {t("insights.correlationRow.experimentTooltip")}
-                </span>
-              </Button>
-              {/* v1.21.0 — the live Coach hand-off sits beside the
-                  roadmap CTA: it scopes to both sources in the pair. */}
+              {/* The Coach hand-off scopes to both sources in the pair. */}
               <AskCoachAction
                 question={t(COACH_QUESTION_BY_KIND[result.kind])}
                 scope={coachScope}