fix: rest_days schema - use 'focus' column instead of 'rest_type'

Problem: get_rest_days_data() queried non-existent 'rest_type' column
Fix: Changed to 'focus' column with correct values (muscle_recovery, cardio_recovery, etc.)

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

backend/data_layer/recovery_metrics.py

@@ -227,9 +227,11 @@ def get_rest_days_data(
         {
             "total_rest_days": int,
             "rest_types": {
-                "strength": int,
-                "cardio": int,
-                "relaxation": int
+                "muscle_recovery": int,
+                "cardio_recovery": int,
+                "mental_rest": int,
+                "deload": int,
+                "injury": int
             },
             "rest_frequency": float,  # days per week
             "confidence": str,
@@ -253,25 +255,27 @@ def get_rest_days_data(
         total_row = cur.fetchone()
         total_count = total_row['count'] if total_row else 0
 
-        # Get breakdown by rest type
+        # Get breakdown by focus type
         cur.execute(
-            """SELECT rest_type, COUNT(*) as count FROM rest_days
+            """SELECT focus, COUNT(*) as count FROM rest_days
                WHERE profile_id=%s AND date >= %s
-               GROUP BY rest_type""",
+               GROUP BY focus""",
             (profile_id, cutoff)
         )
         type_rows = cur.fetchall()
 
         rest_types = {
-            "strength": 0,
-            "cardio": 0,
-            "relaxation": 0
+            "muscle_recovery": 0,
+            "cardio_recovery": 0,
+            "mental_rest": 0,
+            "deload": 0,
+            "injury": 0
         }
 
         for row in type_rows:
-            rest_type = row['rest_type']
-            if rest_type in rest_types:
-                rest_types[rest_type] = row['count']
+            focus = row['focus']
+            if focus in rest_types:
+                rest_types[focus] = row['count']
 
         # Calculate frequency (rest days per week)
         rest_frequency = (total_count / days * 7) if days > 0 else 0.0