fix: update ALL site records in seed, not just is_default_site

Wagtail's initial migration creates a localhost:80 site. Wagtail matches
incoming requests by hostname before ever checking is_default_site, so
updating only the is_default_site record left localhost:80 still pointing
at the Welcome page. Fix by updating root_page on every site.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

apps/core/management/commands/seed_e2e_content.py

@@ -116,17 +116,16 @@ class Command(BaseCommand):
             legal_index.add_child(instance=privacy)
             privacy.save_revision().publish()
 
-        # Update the existing default site (whatever hostname Wagtail created it with)
-        # rather than creating a new 127.0.0.1 entry that leaves localhost pointing
-        # to the Welcome page.
-        site = Site.objects.filter(is_default_site=True).first()
+        # Point every existing Site at the real home page and mark exactly one
+        # as the default.  Wagtail's initial migration creates a localhost:80
+        # site that matches incoming requests by hostname before the
+        # is_default_site fallback is ever reached, so we must update *all*
+        # sites, not just the is_default_site one.
+        Site.objects.all().update(root_page=home, site_name="No Hype AI", is_default_site=False)
+        site = Site.objects.first()
         if site is None:
             site = Site(hostname="localhost", port=80)
-        site.root_page = home
         site.is_default_site = True
-        site.site_name = "No Hype AI"
         site.save()
-        # Remove any other conflicting default-site entries left by test fixtures
-        Site.objects.exclude(pk=site.pk).filter(is_default_site=True).update(is_default_site=False)
 
         self.stdout.write(self.style.SUCCESS("Seeded E2E content."))