feat(coach): close the plan check-in loop on the Today rail

Every accepted coach plan now earns a gentle weekly check-in. Confirming a
plan (proposed → active) without an explicit review date defaults one to a
week out, so a plan is always reviewed, not only the coach's own experiments.

The daily digest emits a single `coach_checkin` rail item when a standing
plan's review has come due — its pinned review date, or a defaulted
activation + 7 days for plans that predate it, or the read-back state a
reviewed plan carries. Capped at one check-in a day across all plans
(earliest-due wins); the rest wait for a following day. It reads existing
plan state only — no fresh generation, nothing warms on mount, and it is
gated on the coach module.

The card offers three one-tap actions through the existing plan-lifecycle
route: keep it (re-arm for another week), adjust it (open the coach), or let
it go (a guilt-free, respected end — the calm inversion of a streak). An
ignored check-in sits quiet and stops resurfacing after about two cycles;
its status is never changed behind the user's back.

Copy lands in all six locales.

src/components/daily/__tests__/today-hero.test.tsx

@@ -1,14 +1,20 @@
 import { describe, it, expect } from "vitest";
 import { renderToStaticMarkup } from "react-dom/server";
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
 
 import { I18nProvider } from "@/lib/i18n/context";
 import { TodayHero } from "../today-hero";
 import type { DailyDigest } from "@/lib/daily/digest";
 import type { PriorityItem } from "@/lib/daily/priority-item";
 
+// The hero now wires the coach check-in card's keep / let-go taps through
+// `useCoachCheckinAction`, so it needs a QueryClient in the tree.
 function render(node: React.ReactNode, locale: "en" | "de" = "en") {
+  const client = new QueryClient();
   return renderToStaticMarkup(
-    <I18nProvider initialLocale={locale}>{node}</I18nProvider>,
+    <QueryClientProvider client={client}>
+      <I18nProvider initialLocale={locale}>{node}</I18nProvider>
+    </QueryClientProvider>,
   );
 }
 

src/components/daily/today-hero.tsx

@@ -36,9 +36,14 @@ import { ScoreRing } from "@/components/insights/derived/score-ring";
 import type { ScoreBand } from "@/components/insights/derived/band-tokens";
 import { ProseBlocks } from "@/components/insights/prose-blocks";
 import { PriorityCard } from "@/components/daily/priority-card";
+import { useCoachCheckinAction } from "@/hooks/use-coach-checkin";
 import { useTranslations } from "@/lib/i18n/context";
 import { cn } from "@/lib/utils";
-import type { DailyDigest } from "@/lib/daily/digest";
+import {
+  COACH_CHECKIN_KEEP_INTENT,
+  COACH_CHECKIN_LETGO_INTENT,
+  type DailyDigest,
+} from "@/lib/daily/digest";
 
 /** Format the server-computed score delta as a signed, muted chip string. */
 function formatDelta(
@@ -53,6 +58,21 @@ function formatDelta(
 
 export function TodayHero({ digest }: { digest: DailyDigest }) {
   const { t } = useTranslations();
+  const { keep, letGo } = useCoachCheckinAction();
+
+  // The coach check-in card's keep / let-go intents carry the plan id after the
+  // ":" (a closed two-intent allowlist); adjust is an href handled by the card
+  // as a <Link>, so it never lands here. Every other rail kind is pure
+  // navigation (dose / sync / preventive), so their taps never call this.
+  const handleAction = (intent: string) => {
+    const keepPrefix = `${COACH_CHECKIN_KEEP_INTENT}:`;
+    const letGoPrefix = `${COACH_CHECKIN_LETGO_INTENT}:`;
+    if (intent.startsWith(keepPrefix)) {
+      keep.mutate(intent.slice(keepPrefix.length));
+    } else if (intent.startsWith(letGoPrefix)) {
+      letGo.mutate(intent.slice(letGoPrefix.length));
+    }
+  };
 
   const hasScore = digest.score !== null;
   const hasItems = digest.worthALook.length > 0;
@@ -174,7 +194,11 @@ export function TodayHero({ digest }: { digest: DailyDigest }) {
             </h2>
             <div className="grid gap-3 sm:grid-cols-2 xl:grid-cols-3">
               {digest.worthALook.map((item, i) => (
-                <PriorityCard key={`${item.kind}-${i}`} item={item} />
+                <PriorityCard
+                  key={`${item.kind}-${i}`}
+                  item={item}
+                  onAction={handleAction}
+                />
               ))}
             </div>
           </div>