fix: resolve go vet error and dayStart logic in ComputeDailyTotals

- Fix 'string(d)' int-to-rune conversion in rpg_test.go by using fmt.Sprintf
- Fix ComputeDailyTotals dayStart logic: initial state should be StateWorking
  when dayStart > 0, correctly counting work from dayStart to first out event
- Update README project structure to reflect new domain/handler/repo layout
- Implement missing achievements: rpg_pioneer (on RPG enable) and
  salary_setter (on first rate set)
- Add tryUnlockAchievement helper to Handler

internal/handler/keyboard.go

@@ -0,0 +1,111 @@
+package handler
+
+import (
+	"fmt"
+
+	"github.com/go-telegram/bot/models"
+)
+
+func mainKeyboard() models.InlineKeyboardMarkup {
+	return models.InlineKeyboardMarkup{
+		InlineKeyboard: [][]models.InlineKeyboardButton{
+			{
+				{Text: "Clock In", CallbackData: "clockin"},
+				{Text: "Clock Out", CallbackData: "clockout"},
+			},
+			{
+				{Text: "Work Type", CallbackData: "worktype"},
+				{Text: "Day Off", CallbackData: "dayoff"},
+			},
+			{
+				{Text: "Report", CallbackData: "report"},
+				{Text: "Export", CallbackData: "export"},
+				{Text: "History", CallbackData: "history"},
+			},
+			{
+				{Text: "RPG", CallbackData: "rpg"},
+				{Text: "League", CallbackData: "league"},
+				{Text: "Burnout", CallbackData: "burnout"},
+			},
+			{
+				{Text: "Salary", CallbackData: "salary"},
+				{Text: "Settings", CallbackData: "settings"},
+			},
+		},
+	}
+}
+
+func backKeyboard() models.InlineKeyboardMarkup {
+	return models.InlineKeyboardMarkup{
+		InlineKeyboard: [][]models.InlineKeyboardButton{
+			{{Text: "Back to Menu", CallbackData: "back_menu"}},
+		},
+	}
+}
+
+func settingsBackKeyboard() models.InlineKeyboardMarkup {
+	return models.InlineKeyboardMarkup{
+		InlineKeyboard: [][]models.InlineKeyboardButton{
+			{{Text: "Back to Settings", CallbackData: "back_settings"}},
+		},
+	}
+}
+
+// buildYearPicker returns a 12-year grid keyboard centered on centerYear.
+func buildYearPicker(cbPrefix, backData, navSuffix string, centerYear int) models.InlineKeyboardMarkup {
+	blockStart := centerYear - 6
+	kbRows := [][]models.InlineKeyboardButton{
+		{
+			{Text: "<", CallbackData: fmt.Sprintf("%syears_%d%s", cbPrefix, blockStart-12, navSuffix)},
+			{Text: fmt.Sprintf("%d", centerYear), CallbackData: "noop"},
+			{Text: ">", CallbackData: fmt.Sprintf("%syears_%d%s", cbPrefix, blockStart+12, navSuffix)},
+		},
+	}
+	for i := 0; i < 12; i += 4 {
+		row := []models.InlineKeyboardButton{}
+		for j := i; j < i+4; j++ {
+			y := blockStart + j
+			row = append(row, models.InlineKeyboardButton{
+				Text: fmt.Sprintf("%d", y), CallbackData: fmt.Sprintf("%syear_%d", cbPrefix, y),
+			})
+		}
+		kbRows = append(kbRows, row)
+	}
+	if backData != "" {
+		kbRows = append(kbRows, []models.InlineKeyboardButton{
+			{Text: "Back", CallbackData: backData},
+		})
+	}
+	return models.InlineKeyboardMarkup{InlineKeyboard: kbRows}
+}
+
+// buildHourPickerKeyboard creates the 24-hour grid for time selection.
+func buildHourPickerKeyboard(cb func(int) string, backData string) models.InlineKeyboardMarkup {
+	kbRows := [][]models.InlineKeyboardButton{}
+	hourRow := []models.InlineKeyboardButton{}
+	for hh := 0; hh < 24; hh++ {
+		hourRow = append(hourRow, models.InlineKeyboardButton{
+			Text: fmt.Sprintf("%02d", hh), CallbackData: cb(hh),
+		})
+		if len(hourRow) == 6 || hh == 23 {
+			kbRows = append(kbRows, hourRow)
+			hourRow = nil
+		}
+	}
+	kbRows = append(kbRows, []models.InlineKeyboardButton{{Text: "Back", CallbackData: backData}})
+	return models.InlineKeyboardMarkup{InlineKeyboard: kbRows}
+}
+
+// buildMinutePickerKeyboard creates the 15-min interval row for minute selection.
+func buildMinutePickerKeyboard(cb func(int) string, backData string) models.InlineKeyboardMarkup {
+	kbRows := [][]models.InlineKeyboardButton{}
+	minRow := []models.InlineKeyboardButton{}
+	for _, mm := range []int{0, 10, 20, 30, 40, 50} {
+		minRow = append(minRow, models.InlineKeyboardButton{
+			Text: fmt.Sprintf("%02d", mm), CallbackData: cb(mm),
+		})
+	}
+	kbRows = append(kbRows, minRow)
+	kbRows = append(kbRows, []models.InlineKeyboardButton{{Text: "Back", CallbackData: backData}})
+	return models.InlineKeyboardMarkup{InlineKeyboard: kbRows}
+}