test: type the new fixtures instead of casting them to never

The fixtures added with these fixes switched the type checker off with
`as never`, which the realism ratchet refuses to see grow. They now carry
their types, three webhook mocks needed no cast at all, and the lowered
counts, with the targets route's one fewer version stamp, are written
back.

src/components/measurements/__tests__/measurement-list-glucose-unit.test.tsx

@@ -61,6 +61,7 @@ vi.mock("@/hooks/use-auth", () => ({
 
 import { I18nProvider } from "@/lib/i18n/context";
 import { MeasurementList } from "../measurement-list";
+import type { Measurement } from "../list/list-model";
 import type { UnitDisplay } from "@/hooks/use-unit-display";
 import { convertGlucose, toCanonicalMgdl } from "@/lib/glucose";
 import { getUnitForType } from "@/lib/measurements/unit-map";
@@ -150,8 +151,15 @@ describe("the out-of-range sentence", () => {
     `${key} ${JSON.stringify(params)}`) as unknown as Parameters<
     typeof outOfRangeMessage
   >[2];
-  const reading = (type: string, unit: string) =>
-    ({ id: "m1", type, value: 1, unit, source: "MANUAL" }) as never;
+  const reading = (type: string, unit: string): Measurement => ({
+    id: "m1",
+    type,
+    value: 1,
+    unit,
+    source: "MANUAL",
+    measuredAt: "2026-11-10T12:00:00.000Z",
+    notes: null,
+  });
   const shows = (unit: string) => ({
     rowDisplay: (m: { value: number }) => ({ value: m.value, unit }),
   });