chore(targets): deprecate the targets page and drop it from the menu

Target editing now lives inline on the insights pages, so the standalone
targets page is no longer a navigation destination. Remove its sidebar
and bottom-nav (overflow) entries and add a top deprecation banner that
points the user at the insights pages and notes the page will be removed
in a future release.

The page stays routable: the /zielwerte to /targets redirect remains and
the route still renders. Removal later is UI-only because the insights
panel consumes the same targets read and threshold-override write. New
deprecation strings land across all six locales.

src/app/targets/__tests__/page.test.tsx

@@ -0,0 +1,93 @@
+import { describe, it, expect, vi } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+
+import { I18nProvider } from "@/lib/i18n/context";
+
+/**
+ * v1.8.6 — `/targets` deprecation banner.
+ *
+ * The Targets (Zielwerte) page is deprecated: target-range editing moved
+ * inline into the Insights category pages. The page stays routable but
+ * carries a top banner telling the user where editing lives now and that
+ * the page will be removed in a future release. This SSR test pins the
+ * banner copy + structure.
+ *
+ * The page leans on `useAuth`, two `useQuery` reads, `useFeatureFlags`
+ * and `useCoachHandoff`; all are stubbed so the render reaches the
+ * banner without standing up an App-Router runtime or a QueryClient.
+ */
+
+vi.mock("@/hooks/use-auth", () => ({
+  useAuth: () => ({
+    isAuthenticated: true,
+    user: { id: "u1", disableCoach: false },
+  }),
+}));
+
+// The page issues two `useQuery` reads (targets payload + provider
+// chain). Drive both off the same stub: the first call resolves the
+// targets payload, the rest return a null provider chain.
+let queryCall = 0;
+const TARGETS_PAYLOAD = {
+  targets: [],
+  bpDiastolic: { current: null, average30: null, range: null },
+  profile: { heightCm: 175, age: 40, gender: "male", glucoseUnit: "mg/dL" },
+};
+vi.mock("@tanstack/react-query", () => ({
+  useQuery: () => {
+    queryCall += 1;
+    if (queryCall === 1) {
+      return { data: TARGETS_PAYLOAD, isLoading: false };
+    }
+    return { data: null, isLoading: false };
+  },
+}));
+
+// Turn Coach off so the page never mounts the SSE drawer machinery.
+vi.mock("@/hooks/use-feature-flags", () => ({
+  useFeatureFlags: () => ({
+    enabled: false,
+    coach: false,
+    briefing: false,
+    insightStatus: false,
+    correlations: false,
+    healthScoreExplainer: false,
+  }),
+}));
+
+vi.mock("@/hooks/use-coach-handoff", () => ({
+  useCoachHandoff: () => ({
+    coachOpen: false,
+    setCoachOpen: vi.fn(),
+    coachPrefill: null,
+    coachScope: null,
+    askCoach: vi.fn(),
+  }),
+}));
+
+const { default: TargetsPage } = await import("../page");
+
+function render(locale: "en" | "de" = "en") {
+  queryCall = 0;
+  return renderToStaticMarkup(
+    <I18nProvider initialLocale={locale}>
+      <TargetsPage />
+    </I18nProvider>,
+  );
+}
+
+describe("<TargetsPage> deprecation banner", () => {
+  it("renders the deprecation banner with title + body", () => {
+    const html = render();
+    expect(html).toContain('data-slot="targets-deprecation"');
+    expect(html).toContain("This page is being retired");
+    expect(html).toContain("Insights");
+    // Reuses the warning-card visual pattern.
+    expect(html).toContain("border-warning");
+  });
+
+  it("localises the banner copy", () => {
+    const html = render("de");
+    expect(html).toContain("Diese Seite wird eingestellt");
+  });
+});

src/app/targets/page.tsx

@@ -1,5 +1,21 @@
 "use client";
 
+// DEPRECATED since v1.8.6. Target-range editing moved inline into the
+// Insights category pages (the per-metric reference panel now mounts the
+// same <TargetEditSheet>), so this standalone page no longer appears in
+// the navigation. It stays routable behind the `/zielwerte`→`/targets`
+// proxy redirect and is a remove candidate after ~10 releases.
+//
+// What stays in place because Insights consumes the same API:
+//   • GET /api/insights/targets — the read powering this page is the
+//     same payload the Insights panel reads (`queryKeys.insightsTargets()`).
+//   • PUT/DELETE /api/user/thresholds — the threshold override write the
+//     inline <TargetEditSheet> calls.
+//   • src/components/targets/* — TargetCard, TargetEditSheet, RangeBar,
+//     ConsistencyStrip, TargetStatusPill, source-link helper are all
+//     reused by the inline Insights panel.
+// Removing the page later is a UI-only change; no data or API moves.
+
 import { useMemo } from "react";
 import { useQuery } from "@tanstack/react-query";
 import { AlertCircle, Loader2 } from "lucide-react";
@@ -200,6 +216,23 @@ export default function TargetsPage() {
         <p className="mt-2 text-sm">{t("targets.introText")}</p>
       </div>
 
+      {/* v1.8.6 — deprecation banner. Target editing moved inline into
+          the Insights category pages; this page stays reachable but will
+          be removed in a future release. */}
+      <Card className="border-warning border-l-4" data-slot="targets-deprecation">
+        <CardContent className="flex gap-3 py-3">
+          <AlertCircle className="text-warning mt-0.5 h-4 w-4 shrink-0" />
+          <div>
+            <p className="text-sm font-medium">
+              {t("targets.deprecation.title")}
+            </p>
+            <p className="text-muted-foreground text-sm">
+              {t("targets.deprecation.body")}
+            </p>
+          </div>
+        </CardContent>
+      </Card>
+
       {/* Profile incomplete hint */}
       {profileIncomplete && (
         <Card className="border-warning border-l-4">