feat(targets): mount CoachDrawer on /targets with per-card scope prefill

The drawer mount + per-card CTA handoff was wired during Phase 5
when the page.tsx was rewritten around the extracted primitives.
This commit lands the integration tests + prompt-builder tests that
pin the contract:

  • targets-coach-mount.test.tsx — three branches:
      1. AI provider configured → per-card "Ask Coach" CTAs render
      2. No AI provider → CTAs hide entirely (no broken-button state)
      3. Chain query still loading → same as #2 (don't render a CTA
         whose click could 404)

  • target-prompts.test.ts — six cases:
      1. EN BP template threads current value + range + cadence + streak
      2. DE BP template threads the same values with German copy
      3. Streak fragment is omitted when streakDays < 3
      4. MOOD_STABILITY uses the verbal label inline ("stable" /
         "variable" / "highly variable") not the raw σ
      5. Unknown target types fall back to a general EN template
      6. DE fallback localises the question shape

  • coachScopeForTarget — four cases:
      1. WEIGHT + BMI map to ["weight"]
      2. BP + BP-in-target map to ["bp"]
      3. MOOD_SCORE + MOOD_STABILITY map to ["mood"]
      4. Unmapped targets return [] so the drawer falls back to defaults

PROMPT_VERSION stays at 4.23.0 per Marc's prompt-version rules:
the assistant-facing system prompt does not change; only the user-
side prefill does. Confirm in the W3e reconcile if a future change
makes a prefill load-bearing on the model's behaviour.

src/app/__tests__/targets-coach-mount.test.tsx

@@ -0,0 +1,133 @@
+import { describe, expect, it, vi } from "vitest";
+import { renderToStaticMarkup } from "react-dom/server";
+
+/**
+ * v1.4.25 W3e — Coach drawer mount + per-card CTA gate.
+ *
+ * Two scenarios:
+ *   1. AI provider configured → per-card "Ask Coach" CTAs render
+ *      alongside each card; the drawer is mounted at the page level.
+ *   2. AI provider NOT configured → CTAs are completely absent (no
+ *      broken-button state) but the drawer mount stays present (it's
+ *      controlled by the parent regardless; no harm in mounting it
+ *      collapsed, and it costs ~0 since closed Sheets render only the
+ *      portal root).
+ */
+
+vi.mock("next/navigation", () => ({
+  useRouter: () => ({ push: vi.fn(), replace: vi.fn() }),
+  usePathname: () => "/targets",
+}));
+
+const sampleData = {
+  targets: [
+    {
+      type: "WEIGHT",
+      label: "Weight",
+      current: 78,
+      average30: 78,
+      trend: "stable",
+      unit: "kg",
+      range: { min: 60, max: 80 },
+      classification: { category: "Normal", color: "#50fa7b" },
+      source: "WHO BMI",
+      daysInRange7d: 5,
+      daysLogged7d: 7,
+      lastMetGoalAt: null,
+      streakDays: 0,
+      insufficientData: false,
+      consistency7d: ["in", "in", "in", "in", "in", "in", "in"],
+    },
+  ],
+  pageSummary: {
+    targetsMetThisWeek: 1,
+    totalTargets: 1,
+    streakHighlight: null,
+  },
+  bpDiastolic: { current: null, average30: null, range: null },
+  profile: { heightCm: 180, age: 35, gender: "MALE", glucoseUnit: null },
+};
+
+let providerChainResponse: { activeProvider: string | null } | null = null;
+
+vi.mock("@tanstack/react-query", () => {
+  const noopClient = {
+    invalidateQueries: vi.fn(),
+    setQueryData: vi.fn(),
+    getQueryData: vi.fn(),
+    refetchQueries: vi.fn(),
+  };
+  return {
+    useQuery: ({ queryKey }: { queryKey: unknown[] }) => {
+      if (Array.isArray(queryKey) && queryKey[1] === "provider-chain") {
+        return {
+          data: providerChainResponse,
+          isLoading: false,
+          isError: false,
+          refetch: vi.fn(),
+        };
+      }
+      return {
+        data: sampleData,
+        isLoading: false,
+        isError: false,
+        refetch: vi.fn(),
+      };
+    },
+    useQueryClient: () => noopClient,
+    useMutation: () => ({
+      mutate: vi.fn(),
+      mutateAsync: vi.fn(),
+      isPending: false,
+      reset: vi.fn(),
+    }),
+  };
+});
+
+vi.mock("@/hooks/use-auth", () => ({
+  useAuth: () => ({
+    user: {
+      id: "u1",
+      username: "marc",
+      email: "marc@example.com",
+      role: "USER",
+    },
+    isAuthenticated: true,
+    isLoading: false,
+    refetch: vi.fn(),
+  }),
+}));
+
+import { I18nProvider } from "@/lib/i18n/context";
+import TargetsPage from "../targets/page";
+
+function render() {
+  return renderToStaticMarkup(
+    <I18nProvider initialLocale="en">
+      <TargetsPage />
+    </I18nProvider>,
+  );
+}
+
+describe("/targets page — Coach drawer mount + CTA gate", () => {
+  it("renders the per-card Coach CTA when an AI provider is configured", () => {
+    providerChainResponse = { activeProvider: "openai" };
+    const html = render();
+    expect(html).toContain('data-slot="target-coach-cta"');
+    expect(html).toContain("Ask Coach");
+  });
+
+  it("hides every per-card Coach CTA when no AI provider is configured", () => {
+    providerChainResponse = { activeProvider: null };
+    const html = render();
+    expect(html).not.toContain('data-slot="target-coach-cta"');
+  });
+
+  it("renders nothing different when chainStatus query is still loading", () => {
+    providerChainResponse = null;
+    const html = render();
+    // Same as the "no provider" branch — until we know the provider is
+    // configured we don't render a CTA whose click would 404.
+    expect(html).not.toContain('data-slot="target-coach-cta"');
+  });
+});

src/lib/ai/coach/__tests__/target-prompts.test.ts

@@ -0,0 +1,129 @@
+import { describe, expect, it } from "vitest";
+
+import { buildTargetPrompt } from "../target-prompts";
+import { coachScopeForTarget } from "../target-scope";
+
+/**
+ * v1.4.25 W3e — per-card Coach prefill builder.
+ *
+ * Pin the per-metric template shape + the locale switch so a
+ * refactor cannot silently flatten the prompts to a single fallback.
+ */
+
+describe("buildTargetPrompt", () => {
+  const base = {
+    current: 124,
+    range: { min: 110, max: 130 },
+    unit: "mmHg",
+    status: "On target",
+    streakDays: 5,
+    daysInRange7d: 6,
+  };
+
+  it("returns the EN BP template with live values", () => {
+    const out = buildTargetPrompt({
+      type: "BLOOD_PRESSURE",
+      locale: "en",
+      ...base,
+    });
+    expect(out).toContain("blood pressure");
+    expect(out).toContain("124 mmHg");
+    expect(out).toContain("110–130 mmHg");
+    expect(out).toContain("6 days");
+    expect(out).toContain("5 days"); // streak
+  });
+
+  it("returns the DE BP template with live values", () => {
+    const out = buildTargetPrompt({
+      type: "BLOOD_PRESSURE",
+      locale: "de",
+      ...base,
+    });
+    expect(out).toContain("Blutdruck-Wert");
+    expect(out).toContain("124 mmHg");
+    expect(out).toContain("110–130 mmHg");
+    expect(out).toContain("6 Tagen");
+  });
+
+  it("omits the streak fragment when streakDays < 3", () => {
+    const out = buildTargetPrompt({
+      type: "BLOOD_PRESSURE",
+      locale: "en",
+      ...base,
+      streakDays: 2,
+    });
+    expect(out).not.toContain("current streak");
+  });
+
+  it("renders the MOOD_STABILITY verbal label inline", () => {
+    const stableOut = buildTargetPrompt({
+      type: "MOOD_STABILITY",
+      locale: "en",
+      ...base,
+      current: 0.5,
+      unit: "σ",
+      range: { min: 0, max: 0.5 },
+    });
+    expect(stableOut).toContain("stable");
+    const variableOut = buildTargetPrompt({
+      type: "MOOD_STABILITY",
+      locale: "en",
+      ...base,
+      current: 1.5,
+      unit: "σ",
+      range: { min: 0, max: 0.5 },
+    });
+    expect(variableOut).toContain("variable");
+    const highOut = buildTargetPrompt({
+      type: "MOOD_STABILITY",
+      locale: "en",
+      ...base,
+      current: 2.5,
+      unit: "σ",
+      range: { min: 0, max: 0.5 },
+    });
+    expect(highOut).toContain("highly variable");
+  });
+
+  it("falls back to the general template for unknown target types", () => {
+    const out = buildTargetPrompt({
+      type: "FUTURE_METRIC_X",
+      locale: "en",
+      ...base,
+    });
+    expect(out).toContain("how I'm doing on");
+    expect(out).toContain("future metric x");
+  });
+
+  it("DE fallback localises the question shape", () => {
+    const out = buildTargetPrompt({
+      type: "FUTURE_METRIC_X",
+      locale: "de",
+      ...base,
+    });
+    expect(out).toContain("Wie steht es um meine");
+  });
+});
+
+describe("coachScopeForTarget", () => {
+  it("maps WEIGHT + BMI to the weight source", () => {
+    expect(coachScopeForTarget("WEIGHT")).toEqual(["weight"]);
+    expect(coachScopeForTarget("BMI")).toEqual(["weight"]);
+  });
+
+  it("maps BLOOD_PRESSURE and BLOOD_PRESSURE_IN_TARGET to bp", () => {
+    expect(coachScopeForTarget("BLOOD_PRESSURE")).toEqual(["bp"]);
+    expect(coachScopeForTarget("BLOOD_PRESSURE_IN_TARGET")).toEqual(["bp"]);
+  });
+
+  it("maps mood + stability to the mood source", () => {
+    expect(coachScopeForTarget("MOOD_SCORE")).toEqual(["mood"]);
+    expect(coachScopeForTarget("MOOD_STABILITY")).toEqual(["mood"]);
+  });
+
+  it("returns an empty array for unmapped targets (use defaults)", () => {
+    expect(coachScopeForTarget("BLOOD_GLUCOSE_FASTING")).toEqual([]);
+    expect(coachScopeForTarget("BODY_FAT")).toEqual([]);
+    expect(coachScopeForTarget("FUTURE_X")).toEqual([]);
+  });
+});