fix(insights): place metric detail back-nav above the heading

The metric values subpage (/insights/values/[type]) and the workout
detail page rendered the back link as the first child of SubPageShell,
which paints it below the page heading. Add an optional backLink slot to
SubPageShell that renders above the header — the standard back-nav
placement — and move both pages' back links into it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
(cherry picked from commit 72a73a52eb8295c9e70a3456972476b8c4469f07)

src/app/insights/values/[type]/page.tsx

@@ -47,20 +47,21 @@ export default function InsightsMetricValuesPage({
     <SubPageShell
       title={t("insights.subPage.valuesPageTitle", { metric: metricLabel })}
       description={t("insights.subPage.valuesPageDescription")}
+      backLink={
+        <Button
+          asChild
+          variant="ghost"
+          size="sm"
+          data-slot="metric-values-back"
+          className="-ml-2 w-fit"
+        >
+          <Link href="/insights">
+            <ArrowLeft className="mr-1 size-4" aria-hidden="true" />
+            {t("insights.subPage.valuesBack")}
+          </Link>
+        </Button>
+      }
     >
-      <Button
-        asChild
-        variant="ghost"
-        size="sm"
-        data-slot="metric-values-back"
-        className="-ml-2 w-fit"
-      >
-        <Link href="/insights">
-          <ArrowLeft className="mr-1 size-4" aria-hidden="true" />
-          {t("insights.subPage.valuesBack")}
-        </Link>
-      </Button>
-
       <MeasurementList lockedType={type} />
     </SubPageShell>
   );

src/app/insights/workouts/[id]/page.tsx

@@ -40,19 +40,21 @@ export default function InsightsWorkoutDetailPage({
     <SubPageShell
       title={t("insights.workouts.title")}
       description={t("insights.workouts.description")}
+      backLink={
+        <Button
+          asChild
+          variant="ghost"
+          size="sm"
+          data-slot="workout-detail-back"
+          className="-ml-2 w-fit"
+        >
+          <Link href="/insights/workouts">
+            <ArrowLeft className="mr-1 size-4" />
+            {t("insights.workouts.detail.backToList")}
+          </Link>
+        </Button>
+      }
     >
-      <Button
-        asChild
-        variant="ghost"
-        size="sm"
-        data-slot="workout-detail-back"
-      >
-        <Link href="/insights/workouts">
-          <ArrowLeft className="mr-1 size-4" />
-          {t("insights.workouts.detail.backToList")}
-        </Link>
-      </Button>
-
       {isLoading ? (
         <div data-slot="workout-detail-loading" className="space-y-3">
           <Skeleton className="h-20 w-full rounded-lg" />

src/app/settings/sources/page.tsx

@@ -1,23 +0,0 @@
-import { permanentRedirect } from "next/navigation";
-
-/**
- * v1.4.34 IW-D — `/settings/sources` permanent redirect.
- *
- * The Sources settings section was merged into `/settings/thresholds`
- * (now titled "Targets & Sources" / "Zielwerte & Quellen"). The two
- * editors share the same per-metric configuration shelf and reading
- * them side-by-side on one page matches how a user actually thinks
- * about metric configuration ("for this metric, which sources do I
- * trust AND what range counts as healthy?"). Per
- * `.planning/research/v1434-r-2-carryover-scope.md` §7 and
- * `.planning/round-v1433-audit-menu.md` §7.1 (item 3).
- *
- * 308 (`permanentRedirect`) keeps the request method intact so any
- * external system that POSTs (none today, but cheap insurance) follows
- * through with its original method. Existing bookmarks, iOS Settings
- * deep-links, and any docs that referenced `/settings/sources`
- * continue to resolve.
- */
-export default function SettingsSourcesRedirect(): never {
-  permanentRedirect("/settings/thresholds");
-}