fix: currency validation, league mobile layout, settings 2-col, burnout ratio, add setusername

- Require both symbol+code in /setcurrency; add preset picker ($ USD,
  T Toman, IRR Rial, EUR, GBP) in settings inline menu
- League: compact 2-line per entry for mobile; sort buttons in 2x2 grid
- Settings: 2-column layout with grouped buttons (timezone+calendar,
  report+report time, break+accent, rpg+league, currency+rate)
- Burnout: cap break ratio at 100% to prevent nonsense values
- Add /setusername command (uses existing SanitizeDisplayName)
- Update /help with new/changed commands

internal/bot/settings.go

@@ -179,29 +179,39 @@ func (h *Handler) settingsCallback(ctx context.Context, chatID int64, msgID int,
 
 // buildSettingsKeyboard returns the settings menu text and inline keyboard.
 func (h *Handler) buildSettingsKeyboard(user *db.User, st *db.UserSettings, breakThreshold int64) (string, models.InlineKeyboardMarkup) {
-	reportStatus := "disabled"
+	reportStatus := "off"
 	if st.ReportEnabled {
-		reportStatus = "enabled"
+		reportStatus = "on"
 	}
-	rpgStatus := "disabled"
+	rpgStatus := "off"
 	if st.RPGEnabled {
-		rpgStatus = "enabled"
+		rpgStatus = "on"
 	}
-	leagueStatus := "disabled"
+	leagueStatus := "off"
 	if st.LeagueOptIn {
 		leagueStatus = "on"
 	}
 	rows := [][]models.InlineKeyboardButton{
-		{{Text: fmt.Sprintf("Timezone: %s", user.Timezone), CallbackData: "timezone"}},
-		{{Text: fmt.Sprintf("Accent: %s", st.ExportAccent), CallbackData: "accent"}},
-		{{Text: fmt.Sprintf("Calendar: %s", user.Calendar), CallbackData: "caltype"}},
-		{{Text: fmt.Sprintf("Report: %s", reportStatus), CallbackData: "reporttoggle"}},
-		{{Text: fmt.Sprintf("Report time: %s", st.ReportTime), CallbackData: "reporttime"}},
-		{{Text: fmt.Sprintf("Break threshold: %dm", breakThreshold/60), CallbackData: "breakthreshold"}},
-		{{Text: fmt.Sprintf("RPG: %s", rpgStatus), CallbackData: "rpgtoggle"}},
-		{{Text: fmt.Sprintf("League: %s", leagueStatus), CallbackData: "leaguetoggle"}},
-		{{Text: fmt.Sprintf("Currency: %s", st.Currency), CallbackData: "currency"}},
-		{{Text: fmt.Sprintf("Rate: %.2f", st.HourlyRate), CallbackData: "setrate"}},
+		{
+			{Text: fmt.Sprintf("Timezone: %s", user.Timezone), CallbackData: "timezone"},
+			{Text: fmt.Sprintf("Calendar: %s", user.Calendar), CallbackData: "caltype"},
+		},
+		{
+			{Text: fmt.Sprintf("Report: %s", reportStatus), CallbackData: "reporttoggle"},
+			{Text: fmt.Sprintf("Report time: %s", st.ReportTime), CallbackData: "reporttime"},
+		},
+		{
+			{Text: fmt.Sprintf("Break: %dm", breakThreshold/60), CallbackData: "breakthreshold"},
+			{Text: fmt.Sprintf("Accent: %s", st.ExportAccent), CallbackData: "accent"},
+		},
+		{
+			{Text: fmt.Sprintf("RPG: %s", rpgStatus), CallbackData: "rpgtoggle"},
+			{Text: fmt.Sprintf("League: %s", leagueStatus), CallbackData: "leaguetoggle"},
+		},
+		{
+			{Text: fmt.Sprintf("Currency: %s", st.Currency), CallbackData: "currency"},
+			{Text: fmt.Sprintf("Rate: %.2f", st.HourlyRate), CallbackData: "setrate"},
+		},
 		{{Text: "Back to Menu", CallbackData: "back_menu"}},
 	}
 	return "Settings:", models.InlineKeyboardMarkup{InlineKeyboard: rows}