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>

Dockerfile

@@ -1,17 +1,49 @@
 # syntax=docker/dockerfile:1
+
+# ---- Stage 1: Build Next.js frontend ----
+FROM node:20-slim AS frontend-build
+WORKDIR /frontend
+COPY werkout-frontend/package.json werkout-frontend/package-lock.json ./
+RUN npm ci
+COPY werkout-frontend/ ./
+ENV NEXT_PUBLIC_API_URL=
+RUN rm -rf .next && npm run build
+
+# ---- Stage 2: Final image (Python + Node runtime) ----
 FROM python:3.9.13
 ENV PYTHONDONTWRITEBYTECODE=1
 ENV PYTHONUNBUFFERED=1
 
-RUN apt-get update
+# System deps
+RUN apt-get update && apt-get install -y \
+    swig libssl-dev dpkg-dev netcat ffmpeg \
+    supervisor curl \
+    && rm -rf /var/lib/apt/lists/*
 
-RUN apt-get install -y swig libssl-dev dpkg-dev netcat ffmpeg
+# Install Node.js 20 for Next.js runtime
+RUN curl -fsSL https://deb.nodesource.com/setup_20.x | bash - \
+    && apt-get install -y nodejs \
+    && rm -rf /var/lib/apt/lists/*
+
+# Python deps
 RUN pip install -U pip
-
 WORKDIR /code
 COPY requirements.txt /code/
 RUN pip install -r requirements.txt
 
+# Copy Django project
 COPY . /code/
 
-RUN /code/manage.py collectstatic --noinput
+# Copy built frontend (overwrite source with built version)
+COPY --from=frontend-build /frontend/.next /code/werkout-frontend/.next
+COPY --from=frontend-build /frontend/node_modules /code/werkout-frontend/node_modules
+
+# Collect static files
+RUN /code/manage.py collectstatic --noinput || true
+
+# Supervisor config
+COPY supervisord.conf /etc/supervisor/conf.d/supervisord.conf
+
+EXPOSE 8000 3000
+
+CMD ["supervisord", "-c", "/etc/supervisor/conf.d/supervisord.conf"]