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/salary.go

@@ -179,7 +179,7 @@ func (h *Handler) handleSetRateMsg(ctx context.Context, msg *models.Message) {
 	h.sendText(ctx, msg.Chat.ID, fmt.Sprintf("Hourly rate set to %s%.2f", currencySymbol(st.Currency), st.HourlyRate))
 }
 
-// handleSetCurrencyMsg handles /setcurrency <symbol> [code].
+// handleSetCurrencyMsg handles /setcurrency <symbol> <code>.
 func (h *Handler) handleSetCurrencyMsg(ctx context.Context, msg *models.Message) {
 	args := strings.TrimSpace(strings.TrimPrefix(msg.Text, "/setcurrency"))
 	if args == "" {
@@ -189,18 +189,23 @@ func (h *Handler) handleSetCurrencyMsg(ctx context.Context, msg *models.Message)
 			return
 		}
 		st, _ := h.DB.GetOrCreateSettings(user.ID)
-		h.sendText(ctx, msg.Chat.ID, fmt.Sprintf("Current currency: %s\nUsage: /setcurrency <symbol> [code]\nExamples:\n/setcurrency $ USD\n/setcurrency EUR\n/setcurrency Toman", st.Currency))
+		h.sendText(ctx, msg.Chat.ID, fmt.Sprintf("Current currency: %s\nUsage: /setcurrency <symbol> <code>\nExamples:\n/setcurrency $ USD\n/setcurrency T Toman\n/setcurrency IRR Rial", st.Currency))
 		return
 	}
 	parts := strings.Fields(args)
-	if len(parts[0]) > 10 || strings.ContainsFunc(parts[0], func(r rune) bool { return r < 32 || r > 126 }) {
-		h.sendText(ctx, msg.Chat.ID, "Invalid currency symbol. Use a short printable string like $, €, £, or Toman.")
+	if len(parts) < 2 {
+		h.sendText(ctx, msg.Chat.ID, "Please provide both symbol and code.\nUsage: /setcurrency <symbol> <code>\nExamples:\n/setcurrency $ USD\n/setcurrency T Toman\n/setcurrency IRR Rial")
 		return
 	}
-	currency := parts[0]
-	if len(parts) >= 2 {
-		currency = parts[0] + " " + parts[1]
+	if len(parts[0]) > 10 || strings.ContainsFunc(parts[0], func(r rune) bool { return r < 32 || r > 126 }) {
+		h.sendText(ctx, msg.Chat.ID, "Invalid currency symbol. Use a short printable string like $, €, £.")
+		return
 	}
+	if len(parts[1]) > 10 || strings.ContainsFunc(parts[1], func(r rune) bool { return r < 32 || r > 126 }) {
+		h.sendText(ctx, msg.Chat.ID, "Invalid currency code.")
+		return
+	}
+	currency := parts[0] + " " + parts[1]
 	user, err := h.getOrCreateUser(msg.Chat.ID)
 	if err != nil {
 		h.sendText(ctx, msg.Chat.ID, "Error loading profile")
@@ -219,7 +224,7 @@ func (h *Handler) handleSetCurrencyMsg(ctx context.Context, msg *models.Message)
 	h.sendText(ctx, msg.Chat.ID, fmt.Sprintf("Currency set to: %s", currency))
 }
 
-// currencyCallback shows currency info (inline).
+// currencyCallback shows the currency picker (inline).
 func (h *Handler) currencyCallback(ctx context.Context, chatID int64, msgID int, callbackID string) {
 	defer h.answerCb(ctx, callbackID)
 	user, err := h.getOrCreateUser(chatID)
@@ -227,12 +232,46 @@ func (h *Handler) currencyCallback(ctx context.Context, chatID int64, msgID int,
 		return
 	}
 	st, _ := h.DB.GetOrCreateSettings(user.ID)
-	text := fmt.Sprintf("Currency: %s\n\nUse /setcurrency <symbol> [code] to change it.\nExamples:\n/setcurrency $ USD\n/setcurrency EUR\n/setcurrency Toman", st.Currency)
-	kb := models.InlineKeyboardMarkup{
-		InlineKeyboard: [][]models.InlineKeyboardButton{
-			{{Text: "Back to Settings", CallbackData: "back_settings"}},
-		},
+	text, kb := buildCurrencyKeyboard(st.Currency)
+	h.editText(ctx, chatID, msgID, text, &kb)
+}
+
+// buildCurrencyKeyboard returns the currency preset picker keyboard.
+func buildCurrencyKeyboard(current string) (string, models.InlineKeyboardMarkup) {
+	presets := []string{"$ USD", "T Toman", "IRR Rial", "€ EUR", "£ GBP"}
+	rows := [][]models.InlineKeyboardButton{}
+	for _, p := range presets {
+		label := p
+		if p == current {
+			label = "> " + label
+		}
+		rows = append(rows, []models.InlineKeyboardButton{
+			{Text: label, CallbackData: "currency_" + p},
+		})
 	}
+	rows = append(rows, []models.InlineKeyboardButton{
+		{Text: "Back to Settings", CallbackData: "back_settings"},
+	})
+	return "Select currency:", models.InlineKeyboardMarkup{InlineKeyboard: rows}
+}
+
+// selectCurrency saves the chosen currency preset.
+func (h *Handler) selectCurrency(ctx context.Context, chatID int64, msgID int, callbackID, currency string) {
+	defer h.answerCb(ctx, callbackID)
+	user, err := h.getOrCreateUser(chatID)
+	if err != nil {
+		return
+	}
+	st, err := h.DB.GetOrCreateSettings(user.ID)
+	if err != nil {
+		return
+	}
+	st.Currency = currency
+	if err := h.DB.UpdateSettings(st); err != nil {
+		return
+	}
+	bt := h.getTodayBreakThreshold(chatID)
+	text, kb := h.buildSettingsKeyboard(user, st, bt)
 	h.editText(ctx, chatID, msgID, text, &kb)
 }