feat(export): promote Arztbericht hero card and shell on settings export

The doctor-report PDF is HealthLog's flagship "data out" path. The
v1.4.16 phase B7 layout treated it as one of five equal cards in the
grid; this change lifts it into a hero card at the top of
`/settings/export`. The remaining four export cards (Measurements CSV,
Medications CSV, Mood CSV, Full JSON backup) move under a dedicated
"Weitere Export-Optionen" / "Other export options" sub-heading.

The hero reuses the `hero-gradient + glow-purple` visual treatment from
the Insights hero strip, so the surface feels consistent across the
app. The CTA routes through the existing `<DoctorReportDialog>` +
`/api/doctor-report` flow — only the framing changed. Mobile-first: at
< sm the CTA falls onto its own row and clears the 44 px WCAG touch
floor (`h-11 sm:h-10`); the button carries an `aria-describedby` link
to the value statement so screen readers announce the framing
alongside the action label.

src/lib/validations/__tests__/measurement.test.ts

@@ -2,6 +2,7 @@ import { describe, expect, it } from "vitest";
 import {
   createMeasurementSchema,
   getUnitForType,
+  listMeasurementsSchema,
   validateMeasurementRange,
 } from "../measurement";
 
@@ -173,4 +174,65 @@ describe("measurement validation", () => {
       }
     });
   });
+
+  // v1.4.37 W7c — list-view "one row per day" mode for cumulative
+  // types. The schema pins the optional `groupBy` enum + `dayKey`
+  // shape; the route gates each branch on whether the resolved type
+  // is in `CUMULATIVE_HK_TYPES`. Tests below pin the parser surface.
+  describe("listMeasurementsSchema — v1.4.37 W7c groupBy + dayKey", () => {
+    it("accepts an omitted groupBy + dayKey (legacy per-sample list)", () => {
+      const parsed = listMeasurementsSchema.safeParse({});
+      expect(parsed.success).toBe(true);
+      if (parsed.success) {
+        expect(parsed.data.groupBy).toBeUndefined();
+        expect(parsed.data.dayKey).toBeUndefined();
+      }
+    });
+
+    it("accepts groupBy=day", () => {
+      const parsed = listMeasurementsSchema.safeParse({
+        type: "ACTIVITY_STEPS",
+        groupBy: "day",
+      });
+      expect(parsed.success).toBe(true);
+      if (parsed.success) {
+        expect(parsed.data.groupBy).toBe("day");
+      }
+    });
+
+    it("rejects an unknown groupBy value", () => {
+      const parsed = listMeasurementsSchema.safeParse({
+        type: "ACTIVITY_STEPS",
+        groupBy: "week",
+      });
+      expect(parsed.success).toBe(false);
+    });
+
+    it("accepts a well-formed YYYY-MM-DD dayKey", () => {
+      const parsed = listMeasurementsSchema.safeParse({
+        type: "ACTIVITY_STEPS",
+        dayKey: "2026-05-15",
+      });
+      expect(parsed.success).toBe(true);
+      if (parsed.success) {
+        expect(parsed.data.dayKey).toBe("2026-05-15");
+      }
+    });
+
+    it("rejects a malformed dayKey (DD.MM.YYYY)", () => {
+      const parsed = listMeasurementsSchema.safeParse({
+        type: "ACTIVITY_STEPS",
+        dayKey: "15.05.2026",
+      });
+      expect(parsed.success).toBe(false);
+    });
+
+    it("rejects a partial dayKey (missing day component)", () => {
+      const parsed = listMeasurementsSchema.safeParse({
+        type: "ACTIVITY_STEPS",
+        dayKey: "2026-05",
+      });
+      expect(parsed.success).toBe(false);
+    });
+  });
 });

src/lib/validations/measurement.ts

@@ -272,6 +272,22 @@ export const listMeasurementsSchema = z.object({
   // when the rollup bucket set is empty for the requested window so
   // brand-new accounts still see correct data on their first chart.
   source: z.enum(["rollup"]).optional(),
+  // v1.4.37 W7c — list-view "one row per day" mode for cumulative
+  // types (steps, active energy, distance, flights, daylight). When
+  // `groupBy=day` is set and `type` is a cumulative HK type, the route
+  // returns one synthesised row per user-TZ day with `value` = SUM
+  // and `sampleCount` = number of per-sample rows behind the bucket.
+  // Omitted = legacy per-sample list behaviour (iOS contract stable).
+  groupBy: z.enum(["day"]).optional(),
+  // v1.4.37 W7c — drill-down to per-sample rows for a single day in
+  // the user's IANA timezone. Format `YYYY-MM-DD`; the route resolves
+  // the day boundary against the user's `User.timezone`. Used by the
+  // expandable list row to reveal the chunks that contributed to the
+  // collapsed daily total.
+  dayKey: z
+    .string()
+    .regex(/^\d{4}-\d{2}-\d{2}$/, "dayKey must be YYYY-MM-DD")
+    .optional(),
 });
 
 export const createBatchMeasurementSchema = z.object({