feat: add projects flow and consolidate default project handling

internal/localdb/converters.go

@@ -19,6 +19,7 @@ func ConfigurationToLocal(cfg *models.Configuration) *LocalConfiguration {
 
 	local := &LocalConfiguration{
 		UUID:             cfg.UUID,
+		ProjectUUID:      cfg.ProjectUUID,
 		IsActive:         true,
 		Name:             cfg.Name,
 		Items:            items,
@@ -61,6 +62,7 @@ func LocalToConfiguration(local *LocalConfiguration) *models.Configuration {
 	cfg := &models.Configuration{
 		UUID:           local.UUID,
 		OwnerUsername:  local.OriginalUsername,
+		ProjectUUID:    local.ProjectUUID,
 		Name:           local.Name,
 		Items:          items,
 		TotalPrice:     local.TotalPrice,
@@ -90,6 +92,40 @@ func derefUint(v *uint) uint {
 	return *v
 }
 
+func ProjectToLocal(project *models.Project) *LocalProject {
+	local := &LocalProject{
+		UUID:          project.UUID,
+		OwnerUsername: project.OwnerUsername,
+		Name:          project.Name,
+		IsActive:      project.IsActive,
+		IsSystem:      project.IsSystem,
+		CreatedAt:     project.CreatedAt,
+		UpdatedAt:     project.UpdatedAt,
+		SyncStatus:    "pending",
+	}
+	if project.ID > 0 {
+		serverID := project.ID
+		local.ServerID = &serverID
+	}
+	return local
+}
+
+func LocalToProject(local *LocalProject) *models.Project {
+	project := &models.Project{
+		UUID:          local.UUID,
+		OwnerUsername: local.OwnerUsername,
+		Name:          local.Name,
+		IsActive:      local.IsActive,
+		IsSystem:      local.IsSystem,
+		CreatedAt:     local.CreatedAt,
+		UpdatedAt:     local.UpdatedAt,
+	}
+	if local.ServerID != nil {
+		project.ID = *local.ServerID
+	}
+	return project
+}
+
 // PricelistToLocal converts models.Pricelist to LocalPricelist
 func PricelistToLocal(pl *models.Pricelist) *LocalPricelist {
 	name := pl.Notification