Fix broken master; ensure all product service APIs have correct implementations (#20663)

* fix broken master; ensure all product service APIs are implemented by the structs passed to products

* use zero allocation interface checks

app/team.go

@@ -24,12 +24,14 @@ import (
 	"github.com/mattermost/mattermost-server/v6/app/users"
 	"github.com/mattermost/mattermost-server/v6/model"
 	"github.com/mattermost/mattermost-server/v6/plugin"
+	"github.com/mattermost/mattermost-server/v6/product"
 	"github.com/mattermost/mattermost-server/v6/shared/i18n"
 	"github.com/mattermost/mattermost-server/v6/shared/mlog"
 	"github.com/mattermost/mattermost-server/v6/store"
 	"github.com/mattermost/mattermost-server/v6/store/sqlstore"
 )
 
+// teamServiceWrapper provides an implementation of `product.TeamService` to be used by products.
 type teamServiceWrapper struct {
 	app AppIface
 }
@@ -42,6 +44,9 @@ func (w *teamServiceWrapper) CreateMember(ctx *request.Context, teamID, userID s
 	return w.app.AddTeamMember(ctx, teamID, userID)
 }
 
+// Ensure the wrapper implements the product service.
+var _ product.TeamService = (*teamServiceWrapper)(nil)
+
 func (a *App) AdjustTeamsFromProductLimits(teamLimits *model.TeamsLimits) *model.AppError {
 	maxActiveTeams := *teamLimits.Active
 	teams, appErr := a.GetAllTeams()