test(slots): make the empty-dates notice assertion clock-safe

Review catch on #23. The test asked for a window starting tomorrow with a
one-minute minimum notice and asserted that nothing was withheld. But
seedNoticeEventType opens availability at 00:00, so tomorrow's first slot is
midnight, and in the last minute of a UTC day the cutoff lands past it
(now 23:59:01 → cutoff 00:00:01). That slot is then correctly withheld, dates is
non-empty, and the test fails — roughly 59 seconds a day, for a reason unrelated
to what it is asserting.

Starts the window at +2 days instead. Every candidate slot is then at least 24
hours beyond any cutoff a one-minute policy can produce, whatever the clock says,
which is the property the file header promises for all of these.

Verified: TestGetSlots_minNoticeDatesEmptyWhenThePolicyCostThisRangeNothing and
TestGetSlots_minNoticeDatesUseTheRequestedTimezone both pass.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: distronode-com

internal/handler/slots_notice_test.go

@@ -103,14 +103,23 @@ func TestGetSlots_omitsMinNoticeWhenThereIsNoPolicy(t *testing.T) {
 }
 
 func TestGetSlots_minNoticeDatesEmptyWhenThePolicyCostThisRangeNothing(t *testing.T) {
-	// A one-minute notice, asked about days that start tomorrow: the policy exists and is
-	// reported, but it took nothing away in this window, so nothing should be explained.
+	// A one-minute notice, asked about days that start the day after tomorrow: the policy
+	// exists and is reported, but it took nothing away in this window, so nothing should
+	// be explained.
+	//
+	// ⚠️ The window deliberately starts at +2 days, not +1. seedNoticeEventType opens
+	// availability at 00:00, so tomorrow's first slot is midnight — and in the last minute
+	// of a UTC day a one-minute notice pushes the cutoff past it (now 23:59:01 → cutoff
+	// 00:00:01), withholding that slot and making dates non-empty. That is a real ~59
+	// seconds a day where this test would fail for a reason unrelated to what it asserts.
+	// Starting a full day later puts every candidate slot at least 24 hours beyond any
+	// cutoff a one-minute policy can produce, whatever the clock says.
 	h, database, _, ownerID := setupWorkspaceWithDB(t)
 	seedNoticeEventType(t, database, ownerID, "tiny-notice", 1)
 
 	now := time.Now().UTC()
-	from := now.AddDate(0, 0, 1).Format("2006-01-02")
-	to := now.AddDate(0, 0, 3).Format("2006-01-02")
+	from := now.AddDate(0, 0, 2).Format("2006-01-02")
+	to := now.AddDate(0, 0, 4).Format("2006-01-02")
 	got := getSlots(t, h, "tiny-notice", "?from="+from+"&to="+to+"&tz=UTC")
 
 	if got.MinNotice == nil {