fix: remove duplicate workspace header and update repo link

- Remove duplicate WorkspaceHeader render (was showing twice)
- Update empty state 'Add Repository' link to point to
  /projects/{id}/settings/repositories instead of old route
- Quality gates: typecheck ✓ lint ✓ build ✓

apps/web/src/pages/repo-workspace.tsx

@@ -164,20 +164,13 @@ export const RepoWorkspace = () => {
           <p>No repositories in this project yet.</p>
           <Link
             className="primary-button"
-            to={`/projects/${projectId}/repositories`}
+            to={`/projects/${projectId}/settings/repositories`}
           >
-            Add Repository
+            Manage Repositories
           </Link>
         </div>
       )}
 
-      {project && (
-        <WorkspaceHeader
-          project={project}
-          currentRepo={selectedRepo || null}
-        />
-      )}
-
       {status === "ready" && repositories.length > 0 && (
         <div className="workspace-layout">
           <aside className="workspace-sidebar">