fix(ticket): close ticket number concurrency gap

internal/migration/000008_sync_lightweight_ticket_permissions.go

@@ -8,7 +8,7 @@ import (
 )
 
 func init() {
-	register(8, "sync lightweight ticket permissions", func() error {
+	register(8, "sync lightweight ticket permissions and reset ticket data", func() error {
 		return sqls.WithTransaction(func(ctx *sqls.TxContext) error {
 			if err := resetLightweightTicketData(ctx.Tx); err != nil {
 				return err

internal/migration/notification_permissions_test.go

@@ -1,6 +1,15 @@
 package migration
 
-import "testing"
+import (
+	"testing"
+	"time"
+
+	"cs-agent/internal/models"
+
+	"github.com/glebarez/sqlite"
+	"gorm.io/gorm"
+	"gorm.io/gorm/schema"
+)
 
 func TestNotificationPermissionMigrationRegistered(t *testing.T) {
 	migration, ok := migrationFuncs[7]
@@ -17,7 +26,71 @@ func TestLightweightTicketPermissionMigrationRegistered(t *testing.T) {
 	if !ok {
 		t.Fatalf("expected migration version 8 to be registered")
 	}
-	if migration.Remark != "sync lightweight ticket permissions" {
+	if migration.Remark != "sync lightweight ticket permissions and reset ticket data" {
 		t.Fatalf("unexpected migration remark: %q", migration.Remark)
 	}
 }
+
+func TestLightweightTicketMigrationResetDeletesTicketData(t *testing.T) {
+	db, err := gorm.Open(sqlite.Open("file:"+t.Name()+"?mode=memory&cache=shared"), &gorm.Config{
+		NamingStrategy: schema.NamingStrategy{
+			TablePrefix:   "t_",
+			SingularTable: true,
+		},
+	})
+	if err != nil {
+		t.Fatalf("open sqlite db: %v", err)
+	}
+	sqlDB, err := db.DB()
+	if err != nil {
+		t.Fatalf("get sqlite db: %v", err)
+	}
+	t.Cleanup(func() {
+		_ = sqlDB.Close()
+	})
+
+	if err := db.AutoMigrate(&models.Ticket{}, &models.TicketTag{}, &models.TicketProgress{}, &models.TicketNoSequence{}); err != nil {
+		t.Fatalf("AutoMigrate() error = %v", err)
+	}
+
+	now := time.Now()
+	ticket := &models.Ticket{
+		TicketNo:    "TK2026050200001",
+		Title:       "legacy ticket",
+		Description: "legacy ticket description",
+		AuditFields: models.AuditFields{CreatedAt: now, UpdatedAt: now},
+	}
+	if err := db.Create(ticket).Error; err != nil {
+		t.Fatalf("create ticket error = %v", err)
+	}
+	if err := db.Create(&models.TicketTag{TicketID: ticket.ID, TagID: 1, AuditFields: models.AuditFields{CreatedAt: now, UpdatedAt: now}}).Error; err != nil {
+		t.Fatalf("create ticket tag error = %v", err)
+	}
+	if err := db.Create(&models.TicketProgress{TicketID: ticket.ID, Content: "legacy progress", CreatedAt: now}).Error; err != nil {
+		t.Fatalf("create ticket progress error = %v", err)
+	}
+	if err := db.Create(&models.TicketNoSequence{DateKey: "20260502", NextSeq: 2, CreatedAt: now, UpdatedAt: now}).Error; err != nil {
+		t.Fatalf("create ticket no sequence error = %v", err)
+	}
+
+	if err := resetLightweightTicketData(db); err != nil {
+		t.Fatalf("resetLightweightTicketData() error = %v", err)
+	}
+
+	assertTableCount(t, db, &models.Ticket{}, 0)
+	assertTableCount(t, db, &models.TicketTag{}, 0)
+	assertTableCount(t, db, &models.TicketProgress{}, 0)
+	assertTableCount(t, db, &models.TicketNoSequence{}, 0)
+}
+
+func assertTableCount(t *testing.T, db *gorm.DB, model any, expected int64) {
+	t.Helper()
+
+	var count int64
+	if err := db.Model(model).Count(&count).Error; err != nil {
+		t.Fatalf("count %T error = %v", model, err)
+	}
+	if count != expected {
+		t.Fatalf("expected %T count %d, got %d", model, expected, count)
+	}
+}