Phase 06 Tier 1: Complete Backend Implementation - Recovery Tracking & Swap System

COMPLETED TASKS:
✅ 06-01: Workout Swap System
   - Added swapped_from_id to workout_logs
   - Created workout_swaps table for history
   - POST /api/workouts/:id/swap endpoint
   - GET /api/workouts/available endpoint
   - Reversible swaps with audit trail

✅ 06-02: Muscle Group Recovery Tracking
   - Created muscle_group_recovery table
   - Implemented calculateRecoveryScore() function
   - GET /api/recovery/muscle-groups endpoint
   - GET /api/recovery/most-recovered endpoint
   - Auto-tracking on workout log completion

✅ 06-03: Smart Workout Recommendations
   - GET /api/recommendations/smart-workout endpoint
   - 7-day workout analysis algorithm
   - Recovery-based filtering (>30% threshold)
   - Top 3 recommendations with context
   - Context-aware reasoning messages

DATABASE CHANGES:
- Added 4 new tables: muscle_group_recovery, workout_swaps, custom_workouts, custom_workout_exercises
- Extended workout_logs with: swapped_from_id, source_type, custom_workout_id, custom_workout_exercise_id
- Created 7 new indexes for performance

IMPLEMENTATION:
- Recovery service with 4 core functions
- 2 new route handlers (recovery, smartRecommendations)
- Updated workouts router with swap endpoints
- Integrated recovery tracking into POST /api/logs
- Full error handling and logging

TESTING:
- Test file created: /backend/test/phase-06-tests.js
- Ready for E2E and staging validation

STATUS: Ready for frontend integration and production review
Branch: feature/06-phase-06

backend/test/phase-06-tests.js

@@ -0,0 +1,77 @@
+const request = require('supertest');
+const app = require('../src/index.js');
+const { Pool } = require('pg');
+
+// Setup database connection for tests
+const pool = new Pool({
+  host: process.env.DB_HOST || 'postgres',
+  port: process.env.DB_PORT || 5432,
+  user: process.env.DB_USER || 'postgres',
+  password: process.env.DB_PASSWORD || 'homelab_postgres_2026',
+  database: process.env.DB_NAME || 'gravl'
+});
+
+describe('Phase 06 - Recovery Tracking & Swap System', () => {
+  let authToken;
+  let userId;
+
+  // Setup: Create test user
+  before(async () => {
+    const res = await request(app)
+      .post('/api/auth/register')
+      .send({
+        email: `test-${Date.now()}@test.com`,
+        password: 'testpass123'
+      });
+
+    authToken = res.body.token;
+    userId = res.body.user.id;
+  });
+
+  describe('06-02: Muscle Group Recovery Tracking', () => {
+    it('GET /api/recovery/muscle-groups - should return recovery status', async () => {
+      const res = await request(app)
+        .get('/api/recovery/muscle-groups')
+        .set('Authorization', `Bearer ${authToken}`);
+
+      expect(res.status).toBe(200);
+      expect(res.body).toHaveProperty('userId');
+      expect(res.body).toHaveProperty('muscleGroups');
+      expect(Array.isArray(res.body.muscleGroups)).toBe(true);
+    });
+
+    it('GET /api/recovery/most-recovered - should return top recovered groups', async () => {
+      const res = await request(app)
+        .get('/api/recovery/most-recovered?limit=3')
+        .set('Authorization', `Bearer ${authToken}`);
+
+      expect(res.status).toBe(200);
+      expect(res.body).toHaveProperty('recovered');
+      expect(res.body.limit).toBe(3);
+    });
+  });
+
+  describe('06-03: Smart Workout Recommendations', () => {
+    it('GET /api/recommendations/smart-workout - should return recommendations', async () => {
+      const res = await request(app)
+        .get('/api/recommendations/smart-workout')
+        .set('Authorization', `Bearer ${authToken}`);
+
+      expect(res.status).toBe(200);
+      expect(res.body).toHaveProperty('recommendations');
+      expect(Array.isArray(res.body.recommendations)).toBe(true);
+    });
+  });
+
+  describe('06-01: Workout Swap System', () => {
+    it('GET /api/workouts/available - should return available exercises', async () => {
+      const res = await request(app)
+        .get('/api/workouts/available')
+        .set('Authorization', `Bearer ${authToken}`);
+
+      expect(res.status).toBe(200);
+      expect(res.body).toHaveProperty('exercises');
+      expect(Array.isArray(res.body.exercises)).toBe(true);
+    });
+  });
+});