refactor: replace skill code with skill ID across the application

- Updated skill handling to use skill IDs instead of skill codes in various components, services, and models.
- Modified tests to reflect changes in skill identification.
- Removed references to skill codes in favor of skill IDs for consistency and clarity.
- Updated localization files to remove skill code references and adjust error messages accordingly.

cmd/testdata/skill/init.go

@@ -6,13 +6,12 @@ import (
 	"agent-desk/internal/models"
 	"agent-desk/internal/repositories"
 	"fmt"
+	"strings"
 	"time"
 
 	"github.com/mlogclub/simple/sqls"
 )
 
-const AfterSalesEscalationSkillCode = seeds.AfterSalesEscalationSkillCode
-
 type InitResult struct {
 	Created int
 	Updated int
@@ -24,7 +23,7 @@ func Init(lang seedlang.Language) (*InitResult, error) {
 	for _, item := range seedItems {
 		itemCopy := item
 		if err := sqls.WithTransaction(func(ctx *sqls.TxContext) error {
-			existing := repositories.SkillDefinitionRepository.Take(ctx.Tx, "code = ?", itemCopy.Code)
+			existing := repositories.SkillDefinitionRepository.Take(ctx.Tx, "name = ?", strings.TrimSpace(itemCopy.Name))
 			if existing != nil {
 				if err := ctx.Tx.Model(existing).Updates(&itemCopy).Error; err != nil {
 					return err
@@ -50,7 +49,6 @@ func buildModels(lang seedlang.Language) []models.SkillDefinition {
 	items := make([]models.SkillDefinition, 0, len(seedItems))
 	for _, seed := range seedItems {
 		items = append(items, models.SkillDefinition{
-			Code:          seed.Code,
 			Name:          seed.Name,
 			Description:   seed.Description,
 			Instruction:   seed.Instruction,