Show team name instead of individual user in Owner column

Projects owned by teams now display the team name in the Owner column
for better organizational continuity when team members change.
Falls back to created_by if no team is assigned.

frontend/src/pages/Home.tsx

@@ -249,7 +249,7 @@ function Home() {
               key: 'created_by',
               header: 'Owner',
               className: 'cell-owner',
-              render: (project) => project.created_by,
+              render: (project) => project.team_name || project.created_by,
             },
             ...(user
               ? [