calendar: a notification's 14:30 is 14:30 here (V-482)

A relay that posts its instant as `2026-08-02T09:00:00Z` handed the wall clock
inside the text that same zone, so «созвон в 14:30» was built as 14:30 UTC and
read back as 18:30 on this UTC+4 box. Every ambient event landed late by the
deploy's own offset, and correct on a UTC box, which is why no test caught it.

Posted is an instant and carries a zone. The clock reading is a wall clock and
carries none, so it resolves against the daemon's zone now. The tests pin
time.Local to +04 in TestMain, so the four hours show up on a UTC runner too.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

internal/calendar/ambient.go

@@ -68,10 +68,19 @@ var dayWords = map[string]int{
 // word ("завтра", "tomorrow") when the notification carries one, and the result
 // is refused if it lands more than ambientPastGrace in the past. A bare start
 // time gets DefaultReminderDuration.
+//
+// The clock reading is read in the daemon's zone (Vikunja #482). Posted is an
+// instant and carries an offset; "созвон в 14:30" is a wall clock and carries
+// none, so the zone has to come from somewhere else. A relay that posts
+// "2026-08-02T09:00:00Z" used to make that 14:30 UTC, which stored an 18:30
+// meeting on a UTC+4 box — wrong by the deploy's own offset, and invisible on a
+// UTC box. The owner's phone and the box share a zone, so the box's zone is the
+// honest reading of a bare wall clock.
 func EventFromNotification(n Notification) (Event, bool) {
 	if n.Posted.IsZero() {
 		return Event{}, false
 	}
+	n.Posted = n.Posted.In(time.Local)
 	line := strings.TrimSpace(n.Title + " " + n.Text)
 	start, end, ok := parseTimeRange(line)
 	if !ok {

internal/calendar/ambient_test.go

@@ -1,12 +1,22 @@
 package calendar
 
 import (
+	"os"
 	"testing"
 	"time"
 )
 
+// A bare clock reading in a notification is read in the daemon's zone, so every
+// test here needs a known one. UTC+4 is the deploy's (Europe/Samara) and it is
+// the offset the 18:30 bug was measured at, so a regression shows up as four
+// hours rather than as nothing at all on a UTC runner.
+func TestMain(m *testing.M) {
+	time.Local = time.FixedZone("+04", 4*3600)
+	os.Exit(m.Run())
+}
+
 func TestEventFromNotification(t *testing.T) {
-	posted := time.Date(2026, 8, 3, 9, 40, 0, 0, time.FixedZone("+04", 4*3600))
+	posted := time.Date(2026, 8, 3, 9, 40, 0, 0, time.Local)
 
 	tests := []struct {
 		name        string
@@ -98,10 +108,10 @@ func TestEventFromNotification(t *testing.T) {
 			if !ev.End.After(ev.Start) {
 				t.Errorf("end %v must be after start %v", ev.End, ev.Start)
 			}
-			// The event lands on the day the phone showed it, in the phone's
-			// location — not shifted into UTC.
-			if ev.Start.Location() != posted.Location() {
-				t.Errorf("location = %v, want %v", ev.Start.Location(), posted.Location())
+			// The event lands on the day the phone showed it, in the daemon's
+			// zone — the clock reading is a wall clock, not an instant.
+			if ev.Start.Location() != time.Local {
+				t.Errorf("location = %v, want %v", ev.Start.Location(), time.Local)
 			}
 			if y, m, d := ev.Start.Date(); y != 2026 || m != time.August || d != 3 {
 				t.Errorf("date = %d-%02d-%02d, want 2026-08-03", y, m, d)
@@ -115,8 +125,7 @@ func TestEventFromNotification(t *testing.T) {
 // the meeting twelve hours in the past and filed it under today in FactKey. A
 // wrong meeting stored is worse than nothing stored.
 func TestEventFromNotificationDayWords(t *testing.T) {
-	loc := time.FixedZone("+04", 4*3600)
-	evening := time.Date(2026, 8, 3, 21, 0, 0, 0, loc)
+	evening := time.Date(2026, 8, 3, 21, 0, 0, 0, time.Local)
 
 	tests := []struct {
 		name        string
@@ -191,7 +200,7 @@ func TestEventFromNotificationDayWords(t *testing.T) {
 func TestEventFromNotificationDropsDayWordFromSummary(t *testing.T) {
 	ev, ok := EventFromNotification(Notification{
 		Title:  "Завтра Планёрка 09:00",
-		Posted: time.Date(2026, 8, 3, 21, 0, 0, 0, time.UTC),
+		Posted: time.Date(2026, 8, 3, 21, 0, 0, 0, time.Local),
 	})
 	if !ok {
 		t.Fatal("expected an event")
@@ -201,6 +210,31 @@ func TestEventFromNotificationDropsDayWordFromSummary(t *testing.T) {
 	}
 }
 
+// Vikunja #482. A relay that posts its instant as UTC used to hand the wall
+// clock inside the text the same zone, so "созвон в 14:30" was stored as 14:30Z
+// and read back as 18:30 on a UTC+4 box — late by exactly the deploy's offset,
+// and correct-looking on a UTC one. Nobody writes a notification meaning 14:30Z.
+func TestEventFromNotificationReadsTheClockAsLocalTime(t *testing.T) {
+	ev, ok := EventFromNotification(Notification{
+		Package: "com.slack",
+		Title:   "Standup",
+		Text:    "созвон в 14:30",
+		Posted:  time.Date(2026, 8, 2, 9, 0, 0, 0, time.UTC), // 13:00 local
+	})
+	if !ok {
+		t.Fatal("expected an event")
+	}
+	if got := ev.Start.Format("15:04"); got != "14:30" {
+		t.Errorf("start = %s, want 14:30 local", got)
+	}
+	if ev.Start.Location() != time.Local {
+		t.Errorf("location = %v, want %v", ev.Start.Location(), time.Local)
+	}
+	if got, want := FactKey(ev), "calendar_event_20260802_Standup"; got != want {
+		t.Errorf("fact key = %q, want %q", got, want)
+	}
+}
+
 func TestEventFromNotificationNeedsPostedAt(t *testing.T) {
 	if _, ok := EventFromNotification(Notification{Title: "Планёрка 10:00"}); ok {
 		t.Error("a notification with no posted_at has no date to sit on")
@@ -211,7 +245,7 @@ func TestEventFromNotificationNeedsPostedAt(t *testing.T) {
 func TestAmbientEventsAreStoredAtReducedConfidence(t *testing.T) {
 	ev, ok := EventFromNotification(Notification{
 		Title:  "Планёрка 10:00-10:30",
-		Posted: time.Date(2026, 8, 3, 9, 0, 0, 0, time.UTC),
+		Posted: time.Date(2026, 8, 3, 9, 0, 0, 0, time.Local),
 	})
 	if !ok {
 		t.Fatal("expected an event")