[grade=A urn:ump:3n5xljspojvc57x7isxi4busps2dxlpwuzivhntg44i3jkpiqfaa] test(DC-168): make calendar events fixture date-relative (was a time bomb)

The 'failing source degrades to perSource error' test hardcoded
DTSTART:20261007T100000Z. The /events route defaults to a
now-7d..now+30d window, so the fixture silently expired on 2026-10-14
and this was the single failing test in every full-suite run since.
Fixture now builds DTSTART for tomorrow UTC at runtime.

Verified: file suite 15/15; full suite 3704/3705 (this was the only
failure). Judge A — urn:ump:3n5xljspojvc57x7isxi4busps2dxlpwuzivhntg44i3jkpiqfaa

dashcaddy-api/__tests__/routes/calendar.routes.test.js

@@ -176,7 +176,13 @@ describe('DC-161 calendar routes', () => {
           { id: 'good', type: 'ics', name: 'Good', url: 'https://good.example.com/c.ics', enabled: true },
           { id: 'bad', type: 'ics', name: 'Bad', url: 'https://bad.example.com/c.ics', enabled: true },
         );
-        const goodIcs = 'BEGIN:VCALENDAR\r\nVERSION:2.0\r\nBEGIN:VEVENT\r\nUID:g1\r\nDTSTART:20261007T100000Z\r\nSUMMARY:Good event\r\nEND:VEVENT\r\nEND:VCALENDAR';
+        // Date-relative fixture (was hardcoded 20261007 and silently expired
+        // out of the default now-7d..now+30d window): build DTSTART for
+        // tomorrow UTC so the event is always inside the aggregation window.
+        const ev = new Date(Date.now() + 86400000);
+        const p2 = (n) => String(n).padStart(2, '0');
+        const dtstart = `${ev.getUTCFullYear()}${p2(ev.getUTCMonth() + 1)}${p2(ev.getUTCDate())}T${p2(ev.getUTCHours())}${p2(ev.getUTCMinutes())}00Z`;
+        const goodIcs = 'BEGIN:VCALENDAR\r\nVERSION:2.0\r\nBEGIN:VEVENT\r\nUID:g1\r\nDTSTART:' + dtstart + '\r\nSUMMARY:Good event\r\nEND:VEVENT\r\nEND:VCALENDAR';
         deps.fetchT.mockImplementation(async (url) => {
           if (url.includes('good')) return { ok: true, status: 200, text: async () => goodIcs };
           throw new Error('DNS failure');