Add phase 3: comments and cooking mode

- Comments on visible recipes; author and admin may delete; per-user
  hourly rate limit (COMMENT_RATE_LIMIT_PER_HOUR)
- Cooking mode with large text, tick-off checklists, serving scaling and
  Screen Wake Lock to keep the display on
- Serving calculator auto-submits on change
- Privacy tests cover comment and cooking-mode URLs

Co-Authored-By: Claude Opus 5.5 <[email protected]>

recipes/migrations/0002_comment.py

@@ -0,0 +1,29 @@
+# Generated by Django 5.2.18 on 2026-10-30 20:37
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('recipes', '0001_initial'),
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Comment',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('text', models.TextField(max_length=2000, verbose_name='Kommentar')),
+                ('created_at', models.DateTimeField(auto_now_add=True)),
+                ('author', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='comments', to=settings.AUTH_USER_MODEL)),
+                ('recipe', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='comments', to='recipes.recipe')),
+            ],
+            options={
+                'ordering': ['created_at'],
+            },
+        ),
+    ]