refactor: break up large functions, add RPG/league/salary/burnout, fix bugs, add tests

- Refactor GenerateMonthlyReport (198→70), HandleCallback (128→85),
  handleHistoryCallback (131→38), handleExportCallback (100→25),
  checkAchievements (86→25) into extracted helper functions
- Add RPG system (XP, levels, streak, achievements, burnout)
- Add WorkTime League leaderboard
- Add salary estimation with configurable currency/rate
- Add input sanitization (SanitizeNote, SanitizeDisplayName)
- Add settings select-style pickers for toggles (report, RPG, league)
- Add break threshold inline picker UI
- Add event notes with pending state and /note command
- Add multi-calendar support (Jalali, Hijri)
- Add Excel export with theme picker
- Fix: getTodayBreakThreshold uses user's timezone (was UTC)
- Fix: acknowledgeCallback passes real callback ID
- Fix: currency symbol safety with currencySymbol() helper
- Fix: count work hours in summary on day-off days
- Fix: unsilence all error returns from SQL Exec/Bot API/migrations
- Remove stale db/schema.sql and unreferenced computeWeekTotals
- Extract constants: DateLayout, TimeLayout, secondsPerHour, etc.
- Add 12 new tests (XP, salary, sanitize, currency, dateutil)
- Remove duplicate package doc comment in totals.go

internal/bot/clock.go

@@ -24,7 +24,7 @@ func (h *Handler) clockIn(chatID int64) (string, error) {
 		loc := loadLocation(user.Timezone)
 		now := time.Now().In(loc)
 		lastTime := time.Unix(last.OccurredAt, 0).In(loc)
-		if lastTime.Format("2006-01-02") == now.Format("2006-01-02") {
+		if lastTime.Format(DateLayout) == now.Format(DateLayout) {
 			return "", errors.New("already clocked in")
 		}
 	}
@@ -35,11 +35,12 @@ func (h *Handler) clockIn(chatID int64) (string, error) {
 	if err := h.DB.CreateEvent(user.ID, day.ID, "in", &wt, now.Unix(), ""); err != nil {
 		return "", err
 	}
-	return fmt.Sprintf("clocked in at %s", now.Format("15:04")), nil
+	return fmt.Sprintf("clocked in at %s", now.Format(TimeLayout)), nil
 }
 
 // clockOut records a clock-out event for today.
 // Returns the formatted time or an error if not clocked in.
+// Also awards XP and updates streaks if RPG is enabled.
 func (h *Handler) clockOut(chatID int64) (string, error) {
 	user, day, err := h.getUserToday(chatID)
 	if err != nil {
@@ -60,7 +61,30 @@ func (h *Handler) clockOut(chatID int64) (string, error) {
 	if err := h.DB.CreateEvent(user.ID, day.ID, "out", nil, now.Unix(), ""); err != nil {
 		return "", err
 	}
-	return fmt.Sprintf("clocked out at %s", now.Format("15:04")), nil
+	text := fmt.Sprintf("clocked out at %s", now.Format(TimeLayout))
+
+	// Award XP and update streaks if RPG enabled
+	st, _ := h.DB.GetOrCreateSettings(user.ID)
+	if st.RPGEnabled {
+		sessionWork := now.Unix() - last.OccurredAt
+		today := now.Format(DateLayout)
+		isWeekend := now.Weekday() == time.Saturday || now.Weekday() == time.Sunday
+
+		streak, _ := h.updateStreak(user.ID, today, true)
+		xp, leveledUp, newLevel, _ := h.computeAndAwardXP(user.ID, sessionWork, streak, today)
+		stats, _ := h.DB.GetOrCreateRPGStats(user.ID)
+		unlocked := h.checkAchievements(user.ID, stats, sessionWork, today, isWeekend)
+
+		text += fmt.Sprintf("\n\n+%d XP (Lv.%d)", xp, newLevel)
+		if leveledUp {
+			text += "\nLevel up!"
+		}
+		for _, a := range unlocked {
+			text += fmt.Sprintf("\nAchievement: %s", a)
+		}
+	}
+
+	return text, nil
 }
 
 // dayOff toggles today as a day off.
@@ -100,11 +124,15 @@ func (h *Handler) toggleReport(chatID int64) (string, error) {
 	if err != nil {
 		return "", err
 	}
-	user.ReportEnabled = !user.ReportEnabled
-	if err := h.DB.UpdateUser(user); err != nil {
+	st, err := h.DB.GetOrCreateSettings(user.ID)
+	if err != nil {
 		return "", err
 	}
-	if user.ReportEnabled {
+	st.ReportEnabled = !st.ReportEnabled
+	if err := h.DB.UpdateSettings(st); err != nil {
+		return "", err
+	}
+	if st.ReportEnabled {
 		return "daily report enabled", nil
 	}
 	return "daily report disabled", nil