fix(monitor): inject time into ComputeDailyBreakdown for testability

Test failed near midnight when outage events fell in previous day's
bucket. Accept a now parameter instead of calling time.Now() internally.

internal/monitor/sla.go

@@ -127,8 +127,7 @@ func ComputeSLA(changes []models.StateChange, currentStatus string, window time.
 	return report
 }
 
-func ComputeDailyBreakdown(changes []models.StateChange, currentStatus string, days int) []DayReport {
-	now := time.Now()
+func ComputeDailyBreakdown(changes []models.StateChange, currentStatus string, days int, now time.Time) []DayReport {
 	reports := make([]DayReport, days)
 
 	for i := 0; i < days; i++ {

internal/monitor/sla_test.go

@@ -118,13 +118,14 @@ func TestComputeSLA_LateNotDown(t *testing.T) {
 }
 
 func TestComputeDailyBreakdown(t *testing.T) {
-	now := time.Now()
+	// Use a fixed time well past midnight so the outage always falls within today's window.
+	now := time.Date(2026, 6, 4, 15, 0, 0, 0, time.UTC)
 	changes := []models.StateChange{
 		{ToStatus: "UP", ChangedAt: now.Add(-1 * time.Hour)},
 		{ToStatus: "DOWN", FromStatus: "UP", ChangedAt: now.Add(-2 * time.Hour)},
 	}
 
-	days := ComputeDailyBreakdown(changes, "UP", 7)
+	days := ComputeDailyBreakdown(changes, "UP", 7, now)
 
 	if len(days) != 7 {
 		t.Fatalf("expected 7 days, got %d", len(days))

internal/tui/update.go

@@ -329,7 +329,7 @@ func (m *Model) recomputeSLA() {
 	}
 
 	m.slaReport = monitor.ComputeSLA(changes, currentStatus, period.duration)
-	m.slaDailyBreakdown = monitor.ComputeDailyBreakdown(changes, currentStatus, period.days)
+	m.slaDailyBreakdown = monitor.ComputeDailyBreakdown(changes, currentStatus, period.days, time.Now())
 
 	m.slaViewport = viewport.New(
 		m.termWidth-chromePadH,