workout generator audit: rules engine, structure rules, split patterns, injury UX, metadata cleanup

- Add rules_engine.py with quantitative rules for all 8 workout types
- Add quality gate retry loop in generate_single_workout()
- Expand calibrate_structure_rules to all 120 combinations (8 types × 5 goals × 3 sections)
- Wire WeeklySplitPattern DB records into _pick_weekly_split()
- Enforce movement patterns from WorkoutStructureRule in exercise selection
- Add straight-set strength support (single main lift, 4-6 rounds)
- Add modality consistency check for duration-dominant workout types
- Add InjuryStep component to onboarding and preferences
- Add sibling exercise exclusion in regenerate and preview_day endpoints
- Display generator warnings on dashboard
- Expand fix_rep_durations, fix_exercise_flags, fix_movement_pattern_typo
- Add audit_exercise_data and check_rules_drift management commands
- Add Next.js frontend with dashboard, onboarding, preferences, history pages
- Add generator app with ML-powered workout generation pipeline
- 96 new tests across 7 test modules

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

superset/migrations/0008_superset_rest_between_rounds.py

@@ -0,0 +1,18 @@
+# Generated by Django 5.1.4 on 2026-02-20 22:55
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('superset', '0007_superset_estimated_time'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='superset',
+            name='rest_between_rounds',
+            field=models.IntegerField(default=45, help_text='Rest between rounds in seconds'),
+        ),
+    ]

superset/migrations/0009_fix_related_names_and_nullable.py

@@ -0,0 +1,25 @@
+# Generated by Django 5.1.4 on 2026-02-21 05:32
+
+import django.db.models.deletion
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('exercise', '0011_fix_related_names_and_nullable'),
+        ('superset', '0008_superset_rest_between_rounds'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='supersetexercise',
+            name='exercise',
+            field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='exercise_supersets', to='exercise.exercise'),
+        ),
+        migrations.AlterField(
+            model_name='supersetexercise',
+            name='superset',
+            field=models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='superset_exercises', to='superset.superset'),
+        ),
+    ]