test: update test files to use @tests.bookhoard.internal domain

Update email domain in remaining test files:
- device_cap_test.go
- device_test.go
- queue_test.go
- refresh_token_test.go
- seven_day_session_test.go

All test files now consistently use the dedicated test domain
to prevent conflicts with real user data.

cmd/server/tests/refresh_token_test.go

@@ -48,7 +48,7 @@ func TestRefreshTokenFlow(t *testing.T) {
 	t.Run("RefreshToken_ValidToken", func(t *testing.T) {
 		// First, login to get tokens
 		loginReq := map[string]string{
-			"login":    "testuser@example.com",
+			"login":    "testuser@tests.bookhoard.internal",
 			"password": "Test@Pass123!",
 		}
 
@@ -133,7 +133,7 @@ func TestRefreshTokenSecurity(t *testing.T) {
 	t.Run("RefreshToken_ReuseProtection", func(t *testing.T) {
 		// Login to get tokens
 		loginReq := map[string]string{
-			"login":    "testuser@example.com",
+			"login":    "testuser@tests.bookhoard.internal",
 			"password": "Test@Pass123!",
 		}
 
@@ -221,7 +221,7 @@ func TestRefreshTokenEdgeCases(t *testing.T) {
 	t.Run("RefreshToken_ResponseStructure", func(t *testing.T) {
 		// Login to get tokens
 		loginReq := map[string]string{
-			"login":    "testuser@example.com",
+			"login":    "testuser@tests.bookhoard.internal",
 			"password": "Test@Pass123!",
 		}
 
@@ -269,7 +269,7 @@ func TestRefreshTokenEdgeCases(t *testing.T) {
 	t.Run("RefreshToken_TokenType", func(t *testing.T) {
 		// Login to get tokens
 		loginReq := map[string]string{
-			"login":    "testuser@example.com",
+			"login":    "testuser@tests.bookhoard.internal",
 			"password": "Test@Pass123!",
 		}