fix(capa): filter owner dropdown by capa_owner role

Was filtering by non-null department, excluding capa_owner
users who had no department set.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BzvzV91UqHZKM9P58qtvrA

app/api/admin/users/route.ts

@@ -60,8 +60,10 @@ export async function POST(request: NextRequest) {
       )
     newUserId = created.user.id
   } else {
+    const appUrl = process.env.NEXT_PUBLIC_APP_URL ?? 'http://localhost:3000'
     const { data: invited, error: inviteError } = await admin.auth.admin.inviteUserByEmail(email, {
       data: { full_name: body.name ?? '' },
+      redirectTo: `${appUrl}/api/auth/callback`,
     })
     if (inviteError || !invited?.user)
       return NextResponse.json({ error: inviteError?.message ?? 'Invite failed' }, { status: 500 })