Remove bbolt database dependency

Replaced bbolt-based database handling with Fyne built-in preferences for storing application settings. Deleted migration logic, database initialization, and error handling related to bbolt, simplifying the codebase and reducing external dependencies.

error/view.go

@@ -1,14 +1,12 @@
 package error
 
 import (
-	"errors"
 	"fyne.io/fyne/v2/container"
 	"fyne.io/fyne/v2/lang"
 	"fyne.io/fyne/v2/widget"
 	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/kernel"
 	"git.kor-elf.net/kor-elf/gui-for-ffmpeg/localizer"
 	"github.com/nicksnyder/go-i18n/v2/i18n"
-	"go.etcd.io/bbolt"
 )
 
 type ViewContract interface {
@@ -37,17 +35,10 @@ func (v View) PanicError(err error) {
 		MessageID: "error",
 	})
 
-	messagetText := err.Error()
-	if errors.Is(err, bbolt.ErrTimeout) {
-		messagetText = v.app.GetLocalizerService().GetMessage(&i18n.LocalizeConfig{
-			MessageID: "errorDatabaseTimeout",
-		})
-	}
-
 	v.app.GetWindow().SetContent(container.NewBorder(
 		container.NewVBox(
 			widget.NewLabel(messageHead),
-			widget.NewLabel(messagetText),
+			widget.NewLabel(err.Error()),
 		),
 		nil,
 		nil,
@@ -57,30 +48,3 @@ func (v View) PanicError(err error) {
 		}),
 	))
 }
-
-func (v View) PanicErrorWriteDirectoryData() {
-	if v.isSetLanguage {
-		v.isSetLanguage = false
-		_ = v.app.GetLocalizerService().SetCurrentLanguageByCode(lang.SystemLocale().LanguageString())
-	}
-
-	message := v.app.GetLocalizerService().GetMessage(&i18n.LocalizeConfig{
-		MessageID: "errorDatabase",
-	})
-	messageHead := v.app.GetLocalizerService().GetMessage(&i18n.LocalizeConfig{
-		MessageID: "error",
-	})
-
-	v.app.GetWindow().SetContent(container.NewBorder(
-		container.NewVBox(
-			widget.NewLabel(messageHead),
-			widget.NewLabel(message),
-		),
-		nil,
-		nil,
-		nil,
-		localizer.LanguageSelectionForm(v.app.GetLocalizerService(), func(lang kernel.Lang) {
-			v.PanicErrorWriteDirectoryData()
-		}),
-	))
-}