fix: Phase 0b - implement active_goals and focus_areas JSON placeholders

Root cause: Two TODO stubs always returned '[]'

Implemented:
- active_goals_json: Calls get_active_goals() from goal_utils
- focus_areas_weighted_json: Builds weighted list with names/categories

Result:
- active_goals_json now shows actual goals
- body_progress_score should calculate correctly
- top_3_goals placeholders will work

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

backend/placeholder_resolver.py

@@ -666,8 +666,9 @@ def _get_active_goals_json(profile_id: str) -> str:
     """Get active goals as JSON string"""
     import json
     try:
-        # TODO: Implement after goal_utils extensions
-        return '[]'
+        from goal_utils import get_active_goals
+        goals = get_active_goals(profile_id)
+        return json.dumps(goals, default=str)
     except Exception:
         return '[]'
 
@@ -676,8 +677,36 @@ def _get_focus_areas_weighted_json(profile_id: str) -> str:
     """Get focus areas with weights as JSON string"""
     import json
     try:
-        # TODO: Implement after goal_utils extensions
-        return '[]'
+        from goal_utils import get_focus_weights_v2, get_db, get_cursor
+
+        weights = get_focus_weights_v2(get_db(), profile_id)
+
+        # Get focus area details
+        with get_db() as conn:
+            cur = get_cursor(conn)
+            cur.execute("""
+                SELECT area_key, name_de, name_en, category
+                FROM focus_area_definitions
+                WHERE is_active = true
+            """)
+            definitions = {row['area_key']: row for row in cur.fetchall()}
+
+        # Build weighted list
+        result = []
+        for area_key, weight in weights.items():
+            if weight > 0 and area_key in definitions:
+                area = definitions[area_key]
+                result.append({
+                    'key': area_key,
+                    'name': area['name_de'],
+                    'category': area['category'],
+                    'weight': weight
+                })
+
+        # Sort by weight descending
+        result.sort(key=lambda x: x['weight'], reverse=True)
+
+        return json.dumps(result, default=str)
     except Exception:
         return '[]'