feat(insights): wire <HeroStrip> + <DailyBriefing> into /insights

Replaces `<InsightsPageHero>` with the new `<HeroStrip>` band and
mounts a full-width `<DailyBriefing>` directly below it, ahead of
the existing advisor + status cards which remain untouched.

`useInsightsAdvisorQuery` now lifts the optional `dailyBriefing`
block off the cached payload and validates it client-side via
`dailyBriefingSchema.safeParse`. A malformed cached briefing falls
back to null so the briefing card paints its empty-state CTA
instead of a half-rendered card. Legacy v1.4.19 cached payloads
(no `dailyBriefing` field) round-trip unchanged.

The CompareToggle migrates from the hero meta band into the
DailyBriefing's metaSlot — keeps the page-level comparison control
adjacent to the briefing it scopes.

The hero greeting reads the user's username (HealthLog has no
separate display-name field) and stops at the first whitespace so
"alice" / "alice.smith" both surface "Good morning, alice".

`insights-polish.test.ts` v1.4.19 A3 ratchet updated: the original
"exactly one onRegenerate prop on the page" assertion was a
string-count check that mis-fires now that the briefing card's
empty-state CTA legitimately wires the same handler. The
load-bearing constraint stays — the advisor card must NOT carry
onRegenerate — and is enforced via a tighter JSX-block check.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/insights/use-insights-advisor.ts

@@ -2,6 +2,10 @@
 
 import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
 import type { InsightResult } from "@/lib/ai/types";
+import {
+  dailyBriefingSchema,
+  type DailyBriefing as DailyBriefingPayload,
+} from "@/lib/ai/schema";
 import { queryKeys } from "@/lib/query-keys";
 
 /**
@@ -26,6 +30,15 @@ export interface InsightAdvisorPayload {
   cached: boolean;
   cachedAt?: string | null;
   legacyPayload?: boolean;
+  /**
+   * v1.4.20 phase B1 — Daily Briefing block surfaced for the new hero
+   * strip + briefing card. Lives on the cached payload alongside the
+   * legacy `insights` shape (see `aiInsightResponseSchema` — the
+   * `.passthrough()` lets the field round-trip through any provider).
+   * Validated client-side via the schema's `safeParse` to keep a
+   * malformed payload from poisoning the briefing card.
+   */
+  dailyBriefing?: DailyBriefingPayload | null;
 }
 
 async function fetchAdvisor(
@@ -46,7 +59,25 @@ async function fetchAdvisor(
     throw new Error(`HTTP ${res.status}`);
   }
   const json = await res.json();
-  return json.data as InsightAdvisorPayload;
+  const payload = json.data as InsightAdvisorPayload;
+  // The cached `insights` blob may carry a `dailyBriefing` from a fresh
+  // PROMPT_VERSION 4.20.x generation. Lift it onto the payload so
+  // consumers don't have to know the legacy shape.
+  const briefingCandidate = (payload?.insights as Record<string, unknown>)
+    ?.dailyBriefing;
+  if (briefingCandidate != null) {
+    const parsed = dailyBriefingSchema.safeParse(briefingCandidate);
+    if (parsed.success) {
+      payload.dailyBriefing = parsed.data;
+    } else {
+      // Malformed cached briefing — keep null so the UI shows the
+      // empty-state CTA instead of a half-rendered card.
+      payload.dailyBriefing = null;
+    }
+  } else {
+    payload.dailyBriefing = null;
+  }
+  return payload;
 }
 
 export interface UseInsightsAdvisorResult {