feat(mental-health): make the wellbeing check-in a standalone module page

Move the PHQ-9 / GAD-7 screener off `/insights/mental-wellbeing` to a
top-level `/mental-wellbeing` route so it no longer borrows the Insights
tab strip and layout shell. The page now uses the standard module-page
frame at the wider content width the other module pages use.

Replace the standing screening disclaimer block and the opt-in/private
line in the header with an info icon after the page heading whose
hover/focus tooltip carries the screening-not-a-diagnosis note. Drop the
now-orphaned `disclaimer` / `optInNote` strings across all six locales
and add the `infoTooltip` string in their place.

The questionnaire, scoring, severity result, PHQ-9 item-9 crisis-resource
handling, focus-on-submit, and 44px touch targets are unchanged. Repoint
the module nav entry and the registry comments at the new route.

src/components/layout/nav-model.ts

@@ -87,10 +87,10 @@ export const NAV_DESTINATIONS: ReadonlyArray<NavDestination> = [
   // Born-gated: `requiresModule: "mentalHealth"` reads the opt-in (default-off)
   // key from the resolved module map, so the entry is absent until the account
   // turns the module on from the Modules hub. The destination is the dedicated
-  // `/insights/mental-wellbeing` check-in surface (its own nav home — the
-  // active-detection helper defers `/insights` to it on that path).
+  // top-level `/mental-wellbeing` check-in surface (its own module page — it
+  // no longer borrows the Insights tab strip / layout shell).
   {
-    href: "/insights/mental-wellbeing",
+    href: "/mental-wellbeing",
     tKey: "nav.mentalWellbeing",
     icon: Brain,
     tourId: "nav-mental-wellbeing",

src/components/mental-health/mental-wellbeing.tsx

@@ -21,6 +21,7 @@ import { apiGet, apiPost } from "@/lib/api/api-fetch";
 import { queryKeys } from "@/lib/query-keys";
 import { Button } from "@/components/ui/button";
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
+import { InfoHint } from "@/components/ui/info-hint";
 import {
   INSTRUMENTS,
   PHQ_GAD_ATTRIBUTION,
@@ -122,20 +123,17 @@ export function MentalWellbeing() {
   );
 
   return (
-    <div className="mx-auto flex max-w-2xl flex-col gap-6">
+    <div className="mx-auto flex max-w-3xl flex-col gap-6">
       <header className="flex flex-col gap-2">
-        <h1 className="text-2xl font-semibold">
-          {t("mentalHealth.pageTitle")}
-        </h1>
+        <div className="flex items-center gap-1.5">
+          <h1 className="text-2xl font-semibold">
+            {t("mentalHealth.pageTitle")}
+          </h1>
+          <InfoHint label={t("mentalHealth.infoTooltip")} />
+        </div>
         <p className="text-muted-foreground text-sm">
           {t("mentalHealth.pageDescription")}
         </p>
-        <p className="text-muted-foreground border-border/60 bg-muted/40 rounded-md border p-3 text-xs">
-          {t("mentalHealth.disclaimer")}
-        </p>
-        <p className="text-muted-foreground text-xs">
-          {t("mentalHealth.optInNote")}
-        </p>
       </header>
 
       {phase === "choose" && (