feat: goal categories and priorities - backend + API

Implemented multi-dimensional goal priorities (Option B).

**Backend Changes:**
- Migration 028: Added `category` + `priority` columns to goals table
- Auto-migration of existing goals to categories based on goal_type
- GoalCreate/GoalUpdate models extended with category + priority
- New endpoint: GET /api/goals/grouped (returns goals by category)
- Categories: body, training, nutrition, recovery, health, other
- Priorities: 1=high (⭐⭐⭐), 2=medium (⭐⭐), 3=low (⭐)

**API Changes:**
- Added api.listGoalsGrouped() binding

**Frontend (partial):**
- Added GOAL_CATEGORIES + PRIORITY_LEVELS constants
- Extended formData with category + priority fields
- Removed "Gewichtung gesamt" display (useless)
- Load groupedGoals in addition to flat goals list

Next: Complete frontend UI rebuild for category grouping

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

backend/migrations/028_goal_categories_priorities.sql

@@ -0,0 +1,58 @@
+-- Migration 028: Goal Categories and Priorities
+-- Date: 2026-03-27
+-- Purpose: Multi-dimensional goal priorities (one primary goal per category)
+
+-- ============================================================================
+-- Add category and priority columns
+-- ============================================================================
+
+ALTER TABLE goals
+ADD COLUMN category VARCHAR(50),
+ADD COLUMN priority INTEGER DEFAULT 2 CHECK (priority >= 1 AND priority <= 3);
+
+COMMENT ON COLUMN goals.category IS 'Goal category: body, training, nutrition, recovery, health, other';
+COMMENT ON COLUMN goals.priority IS 'Priority level: 1=high, 2=medium, 3=low';
+
+-- ============================================================================
+-- Migrate existing goals to categories based on goal_type
+-- ============================================================================
+
+UPDATE goals SET category = CASE
+  -- Body composition goals
+  WHEN goal_type IN ('weight', 'body_fat', 'lean_mass') THEN 'body'
+
+  -- Training goals
+  WHEN goal_type IN ('strength', 'flexibility', 'training_frequency') THEN 'training'
+
+  -- Health/cardio goals
+  WHEN goal_type IN ('vo2max', 'rhr', 'bp', 'hrv') THEN 'health'
+
+  -- Recovery goals
+  WHEN goal_type IN ('sleep_quality', 'sleep_duration', 'rest_days') THEN 'recovery'
+
+  -- Nutrition goals
+  WHEN goal_type IN ('calories', 'protein', 'healthy_eating') THEN 'nutrition'
+
+  -- Default
+  ELSE 'other'
+END
+WHERE category IS NULL;
+
+-- ============================================================================
+-- Set priority based on is_primary
+-- ============================================================================
+
+UPDATE goals SET priority = CASE
+  WHEN is_primary = true THEN 1  -- Primary goals get priority 1
+  ELSE 2                          -- Others get priority 2 (medium)
+END;
+
+-- ============================================================================
+-- Create index for category-based queries
+-- ============================================================================
+
+CREATE INDEX IF NOT EXISTS idx_goals_category_priority
+ON goals(profile_id, category, priority)
+WHERE is_active = true;
+
+COMMENT ON INDEX idx_goals_category_priority IS 'Fast lookup for category-grouped goals sorted by priority';

backend/routers/goals.py

@@ -42,10 +42,12 @@ class FocusAreasUpdate(BaseModel):
 class GoalCreate(BaseModel):
     """Create or update a concrete goal"""
     goal_type: str  # weight, body_fat, lean_mass, vo2max, strength, flexibility, bp, rhr
-    is_primary: bool = False
+    is_primary: bool = False  # Kept for backward compatibility
     target_value: float
     unit: str  # kg, %, ml/kg/min, bpm, mmHg, cm, reps
     target_date: Optional[date] = None
+    category: Optional[str] = 'other'  # body, training, nutrition, recovery, health, other
+    priority: Optional[int] = 2  # 1=high, 2=medium, 3=low
     name: Optional[str] = None
     description: Optional[str] = None
 
@@ -54,7 +56,9 @@ class GoalUpdate(BaseModel):
     target_value: Optional[float] = None
     target_date: Optional[date] = None
     status: Optional[str] = None  # active, reached, abandoned, expired
-    is_primary: Optional[bool] = None
+    is_primary: Optional[bool] = None  # Kept for backward compatibility
+    category: Optional[str] = None  # body, training, nutrition, recovery, health, other
+    priority: Optional[int] = None  # 1=high, 2=medium, 3=low
     name: Optional[str] = None
     description: Optional[str] = None
 
@@ -403,13 +407,13 @@ def create_goal(data: GoalCreate, session: dict = Depends(require_auth)):
             INSERT INTO goals (
                 profile_id, goal_type, is_primary,
                 target_value, current_value, start_value, unit,
-                target_date, name, description
-            ) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
+                target_date, category, priority, name, description
+            ) VALUES (%s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s, %s)
             RETURNING id
         """, (
             pid, data.goal_type, data.is_primary,
             data.target_value, current_value, current_value, data.unit,
-            data.target_date, data.name, data.description
+            data.target_date, data.category, data.priority, data.name, data.description
         ))
 
         goal_id = cur.fetchone()['id']
@@ -461,6 +465,14 @@ def update_goal(goal_id: str, data: GoalUpdate, session: dict = Depends(require_
             updates.append("is_primary = %s")
             params.append(data.is_primary)
 
+        if data.category is not None:
+            updates.append("category = %s")
+            params.append(data.category)
+
+        if data.priority is not None:
+            updates.append("priority = %s")
+            params.append(data.priority)
+
         if data.name is not None:
             updates.append("name = %s")
             params.append(data.name)
@@ -499,6 +511,52 @@ def delete_goal(goal_id: str, session: dict = Depends(require_auth)):
 
         return {"message": "Ziel gelöscht"}
 
+@router.get("/grouped")
+def get_goals_grouped(session: dict = Depends(require_auth)):
+    """
+    Get goals grouped by category, sorted by priority.
+
+    Returns structure:
+    {
+      "body": [{"id": "...", "goal_type": "weight", "priority": 1, ...}, ...],
+      "training": [...],
+      "nutrition": [...],
+      "recovery": [...],
+      "health": [...],
+      "other": [...]
+    }
+    """
+    pid = session['profile_id']
+
+    with get_db() as conn:
+        cur = get_cursor(conn)
+
+        # Get all active goals with type definitions
+        cur.execute("""
+            SELECT
+                g.id, g.goal_type, g.target_value, g.current_value, g.start_value,
+                g.unit, g.target_date, g.status, g.is_primary, g.category, g.priority,
+                g.name, g.description, g.progress_pct, g.linear_projection,
+                g.created_at, g.updated_at,
+                gt.label_de, gt.icon, gt.category as type_category
+            FROM goals g
+            LEFT JOIN goal_type_definitions gt ON g.goal_type = gt.type_key
+            WHERE g.profile_id = %s AND g.is_active = true
+            ORDER BY g.category, g.priority ASC, g.created_at DESC
+        """, (pid,))
+
+        goals = cur.fetchall()
+
+        # Group by category
+        grouped = {}
+        for goal in goals:
+            cat = goal['category'] or 'other'
+            if cat not in grouped:
+                grouped[cat] = []
+            grouped[cat].append(r2d(goal))
+
+        return grouped
+
 # ============================================================================
 # Training Phases
 # ============================================================================

frontend/src/utils/api.js

@@ -340,6 +340,7 @@ export const api = {
   updateFocusAreas:       (d)     => req('/goals/focus-areas', jput(d)),
 
   listGoals:              ()      => req('/goals/list'),
+  listGoalsGrouped:       ()      => req('/goals/grouped'),
   createGoal:             (d)     => req('/goals/create', json(d)),
   updateGoal:             (id,d)  => req(`/goals/${id}`, jput(d)),
   deleteGoal:             (id)    => req(`/goals/${id}`, {method:'DELETE'}),