fix(store,due): poll the clock so today turns over after sleep

tests/due.test.ts

@@ -4,7 +4,6 @@ import {
   dueLabel,
   dueTone,
   nextFriday,
-  untilMidnight,
 } from "../src/lib/due";
 
 describe("due helpers read the day they are given", () => {
@@ -26,12 +25,4 @@ describe("due helpers read the day they are given", () => {
     expect(nextFriday("2026-08-23")).toBe("2026-08-28");
     expect(nextFriday("2026-08-28")).toBe("2026-09-04");
   });
-
-  it("arms the midnight timer for the coming midnight", () => {
-    const late = new Date(2026, 7, 23, 23, 59, 0);
-    expect(untilMidnight(late)).toBeGreaterThan(60_000);
-    expect(untilMidnight(late)).toBeLessThan(62_000);
-    const early = new Date(2026, 7, 23, 0, 0, 1);
-    expect(untilMidnight(early)).toBeGreaterThan(23 * 3_600_000);
-  });
 });