feat: replace hardcoded navigation with CMS-managed models

Replace static nav/footer links with Wagtail-managed NavigationMenuItem
and SocialMediaLink orderables on SiteSettings. Unpublished pages are
automatically excluded from rendering, fixing the dead-link problem.

- Extend SiteSettings with site_name, tagline, footer_description,
  copyright_text branding fields
- Add NavigationMenuItem orderable (link_page/link_url, show_in_header,
  show_in_footer, sort_order) with automatic live-page filtering
- Add SocialMediaLink orderable with platform icon templates
- New template tags: get_nav_items, get_social_links
- Update nav.html and footer.html to render from CMS data
- Data migration seeds existing hardcoded values for zero-change deploy
- Update seed_e2e_content command for test/dev environments
- 18 new tests covering models, template tags, and rendered output

Closes #32

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

apps/core/migrations/0002_sitesettings_copyright_text_and_more.py

@@ -0,0 +1,69 @@
+# Generated by Django 5.2.11 on 2026-03-02 18:39
+
+import django.db.models.deletion
+import modelcluster.fields
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0001_initial'),
+        ('wagtailcore', '0094_alter_page_locale'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='sitesettings',
+            name='copyright_text',
+            field=models.CharField(default='No Hype AI. All rights reserved.', max_length=200),
+        ),
+        migrations.AddField(
+            model_name='sitesettings',
+            name='footer_description',
+            field=models.TextField(blank=True, default='In-depth reviews and benchmarks of the latest AI coding tools.\nHonest analysis for developers.'),
+        ),
+        migrations.AddField(
+            model_name='sitesettings',
+            name='site_name',
+            field=models.CharField(default='NO HYPE AI', max_length=100),
+        ),
+        migrations.AddField(
+            model_name='sitesettings',
+            name='tagline',
+            field=models.CharField(default='Honest AI tool reviews for developers.', max_length=200),
+        ),
+        migrations.CreateModel(
+            name='NavigationMenuItem',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('sort_order', models.IntegerField(blank=True, editable=False, null=True)),
+                ('link_url', models.URLField(blank=True, default='', help_text='External URL (used only when no page is selected).')),
+                ('link_title', models.CharField(blank=True, default='', help_text='Override the display text. If blank, the page title is used.', max_length=100)),
+                ('open_in_new_tab', models.BooleanField(default=False)),
+                ('show_in_header', models.BooleanField(default=True)),
+                ('show_in_footer', models.BooleanField(default=True)),
+                ('link_page', models.ForeignKey(blank=True, help_text='Link to an internal page. If unpublished, the link is hidden automatically.', null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='+', to='wagtailcore.page')),
+                ('settings', modelcluster.fields.ParentalKey(on_delete=django.db.models.deletion.CASCADE, related_name='navigation_items', to='core.sitesettings')),
+            ],
+            options={
+                'ordering': ['sort_order'],
+                'abstract': False,
+            },
+        ),
+        migrations.CreateModel(
+            name='SocialMediaLink',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('sort_order', models.IntegerField(blank=True, editable=False, null=True)),
+                ('platform', models.CharField(choices=[('twitter', 'Twitter / X'), ('github', 'GitHub'), ('rss', 'RSS Feed'), ('linkedin', 'LinkedIn'), ('youtube', 'YouTube'), ('mastodon', 'Mastodon'), ('bluesky', 'Bluesky')], max_length=30)),
+                ('url', models.URLField()),
+                ('label', models.CharField(blank=True, default='', help_text='Display label. If blank, the platform name is used.', max_length=100)),
+                ('settings', modelcluster.fields.ParentalKey(on_delete=django.db.models.deletion.CASCADE, related_name='social_links', to='core.sitesettings')),
+            ],
+            options={
+                'ordering': ['sort_order'],
+                'abstract': False,
+            },
+        ),
+    ]

apps/core/migrations/0003_seed_navigation_data.py

@@ -0,0 +1,112 @@
+# Generated by Django 5.2.11 on 2026-03-02 18:39
+
+from django.db import migrations
+
+
+def seed_navigation_data(apps, schema_editor):
+    Site = apps.get_model("wagtailcore", "Site")
+    SiteSettings = apps.get_model("core", "SiteSettings")
+    NavigationMenuItem = apps.get_model("core", "NavigationMenuItem")
+    SocialMediaLink = apps.get_model("core", "SocialMediaLink")
+    Page = apps.get_model("wagtailcore", "Page")
+
+    for site in Site.objects.all():
+        settings, _ = SiteSettings.objects.get_or_create(site=site)
+
+        # Only seed if no nav items exist yet
+        if NavigationMenuItem.objects.filter(settings=settings).exists():
+            continue
+
+        root_page = site.root_page
+        if not root_page:
+            continue
+
+        # Find pages by slug under the site root using tree path
+        home_page = root_page
+        # In Wagtail's treebeard, direct children share the root's path prefix
+        articles_page = Page.objects.filter(
+            depth=root_page.depth + 1,
+            path__startswith=root_page.path,
+            slug__startswith="articles",
+        ).first()
+        about_page = Page.objects.filter(
+            depth=root_page.depth + 1,
+            path__startswith=root_page.path,
+            slug__startswith="about",
+        ).first()
+
+        nav_items = []
+        if home_page:
+            nav_items.append(
+                NavigationMenuItem(
+                    settings=settings,
+                    link_page=home_page,
+                    link_title="Home",
+                    show_in_header=True,
+                    show_in_footer=True,
+                    sort_order=0,
+                )
+            )
+        if articles_page:
+            nav_items.append(
+                NavigationMenuItem(
+                    settings=settings,
+                    link_page=articles_page,
+                    link_title="Articles",
+                    show_in_header=True,
+                    show_in_footer=True,
+                    sort_order=1,
+                )
+            )
+        if about_page:
+            nav_items.append(
+                NavigationMenuItem(
+                    settings=settings,
+                    link_page=about_page,
+                    link_title="About",
+                    show_in_header=True,
+                    show_in_footer=True,
+                    sort_order=2,
+                )
+            )
+        NavigationMenuItem.objects.bulk_create(nav_items)
+
+        # Social links
+        if not SocialMediaLink.objects.filter(settings=settings).exists():
+            SocialMediaLink.objects.bulk_create(
+                [
+                    SocialMediaLink(
+                        settings=settings,
+                        platform="twitter",
+                        url="https://twitter.com/nohypeai",
+                        label="Twitter (X)",
+                        sort_order=0,
+                    ),
+                    SocialMediaLink(
+                        settings=settings,
+                        platform="rss",
+                        url="/feed/",
+                        label="RSS Feed",
+                        sort_order=1,
+                    ),
+                ]
+            )
+
+
+def reverse_seed(apps, schema_editor):
+    NavigationMenuItem = apps.get_model("core", "NavigationMenuItem")
+    SocialMediaLink = apps.get_model("core", "SocialMediaLink")
+    NavigationMenuItem.objects.all().delete()
+    SocialMediaLink.objects.all().delete()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0002_sitesettings_copyright_text_and_more'),
+        ('wagtailcore', '0094_alter_page_locale'),
+    ]
+
+    operations = [
+        migrations.RunPython(seed_navigation_data, reverse_seed),
+    ]