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>

werkout-frontend/components/ui/Card.tsx

@@ -0,0 +1,23 @@
+import type { ReactNode, HTMLAttributes } from "react";
+
+interface CardProps extends HTMLAttributes<HTMLDivElement> {
+  className?: string;
+  children: ReactNode;
+  onClick?: () => void;
+}
+
+export function Card({ className = "", children, onClick, ...rest }: CardProps) {
+  return (
+    <div
+      onClick={onClick}
+      className={`
+        bg-zinc-900 border border-zinc-700/50 rounded-xl
+        ${onClick ? "hover:bg-zinc-800/50 cursor-pointer transition-colors duration-150" : ""}
+        ${className}
+      `}
+      {...rest}
+    >
+      {children}
+    </div>
+  );
+}