feat: Hijri calendar, virtual midnight crossover, overlap rejection, WAL mode

- Hijri (قمری) calendar added as 3rd calendar option with tabular conversion
- Calendar type select menu (like accent) with gregorian/jalali/hijri
- Calendar type applied to exports and reports
- Midnight crossover: virtual splits at computation time (no synthetic DB events)
  - Handles both UTC and local timezone boundaries
  - Timezone changes handled naturally (recomputed on-the-fly)
- Rate limiting per user ID instead of chat ID
- WAL mode enabled for SQLite
- Smart reply keyboard updates after every state change
- Overlapping time edits rejected (must preserve in/out alternation)
- Single event deletion warns if timeline needs repair
- Day off no longer prevents clock in/out
- Accent colors shown with descriptive names in select menu
- Delete button label changed to DEL for visual distinction

internal/bot/totals.go

@@ -20,7 +20,7 @@ type DailyTotals struct {
 	PairCount    int
 }
 
-func ComputeDailyTotals(events []db.Event, minBreakThreshold int64) DailyTotals {
+func ComputeDailyTotals(events []db.Event, minBreakThreshold int64, dayStart, dayEnd int64) DailyTotals {
 	if len(events) == 0 {
 		return DailyTotals{}
 	}
@@ -30,6 +30,15 @@ func ComputeDailyTotals(events []db.Event, minBreakThreshold int64) DailyTotals
 		return sorted[i].OccurredAt < sorted[j].OccurredAt
 	})
 
+	if dayStart > 0 && len(sorted) > 0 && sorted[0].EventType == "out" {
+		first := db.Event{EventType: "in", OccurredAt: dayStart}
+		sorted = append([]db.Event{first}, sorted...)
+	}
+	if dayEnd > 0 && len(sorted) > 0 && sorted[len(sorted)-1].EventType == "in" {
+		last := db.Event{EventType: "out", OccurredAt: dayEnd}
+		sorted = append(sorted, last)
+	}
+
 	var workTotal, breakTotal int64
 	var workStart, breakStart int64
 	pairs := 0