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.

internal/ai/runtime/reply_service_test.go

@@ -72,8 +72,8 @@ func TestResolveReplyTimeout(t *testing.T) {
 
 func TestBuildRunLogPlan(t *testing.T) {
 	summary := &applicationruntime.Summary{
-		PlannedSkillCode: "faq_router",
-		PlanReason:       "manual",
+		PlannedSkillID: 44,
+		PlanReason:     "manual",
 	}
 	action, toolCode, reason := buildRunLogPlan(summary)
 	if action != "skill" || toolCode != "" || reason != "manual" {