feat: dynamic schema dropdowns for goal type admin UI

Admin can now easily create custom goal types:
- New endpoint /api/goals/schema-info with table/column metadata
- 9 tables documented (weight, caliper, activity, nutrition, sleep, vitals, BP, rest_days, circumference)
- Table dropdown with descriptions (e.g., 'activity_log - Trainingseinheiten')
- Column dropdown dependent on selected table
- All columns documented in German with data types
- Fields optional (for complex calculation formulas)

UX improvements:
- No need to guess table/column names
- Clear descriptions for each field
- Type-safe selection (no typos)
- Cascading dropdowns (column depends on table)

Closes user feedback: 'Admin weiß nicht welche Tabellen/Spalten verfügbar sind'

backend/routers/goals.py

@@ -508,6 +508,108 @@ def _calculate_norm_category(test_type: str, value: float, unit: str) -> Optiona
 # Goal Type Definitions (Phase 1.5 - Flexible Goal System)
 # ============================================================================
 
+@router.get("/schema-info")
+def get_schema_info(session: dict = Depends(require_auth)):
+    """
+    Get available tables and columns for goal type creation.
+
+    Admin-only endpoint for building custom goal types.
+    Returns structure with descriptions for UX guidance.
+    """
+    pid = session['profile_id']
+
+    # Check admin role
+    with get_db() as conn:
+        cur = get_cursor(conn)
+        cur.execute("SELECT role FROM profiles WHERE id = %s", (pid,))
+        profile = cur.fetchone()
+
+        if not profile or profile['role'] != 'admin':
+            raise HTTPException(status_code=403, detail="Admin-Zugriff erforderlich")
+
+    # Define relevant tables with descriptions
+    # Only include tables that make sense for goal tracking
+    schema = {
+        "weight_log": {
+            "description": "Gewichtsverlauf",
+            "columns": {
+                "weight": {"type": "DECIMAL", "description": "Körpergewicht in kg"}
+            }
+        },
+        "caliper_log": {
+            "description": "Caliper-Messungen (Hautfalten)",
+            "columns": {
+                "body_fat_pct": {"type": "DECIMAL", "description": "Körperfettanteil in %"},
+                "sum_mm": {"type": "DECIMAL", "description": "Summe Hautfalten in mm"}
+            }
+        },
+        "circumference_log": {
+            "description": "Umfangsmessungen",
+            "columns": {
+                "c_neck": {"type": "DECIMAL", "description": "Nackenumfang in cm"},
+                "c_chest": {"type": "DECIMAL", "description": "Brustumfang in cm"},
+                "c_waist": {"type": "DECIMAL", "description": "Taillenumfang in cm"},
+                "c_hips": {"type": "DECIMAL", "description": "Hüftumfang in cm"},
+                "c_thigh_l": {"type": "DECIMAL", "description": "Oberschenkel links in cm"},
+                "c_thigh_r": {"type": "DECIMAL", "description": "Oberschenkel rechts in cm"},
+                "c_calf_l": {"type": "DECIMAL", "description": "Wade links in cm"},
+                "c_calf_r": {"type": "DECIMAL", "description": "Wade rechts in cm"},
+                "c_bicep_l": {"type": "DECIMAL", "description": "Bizeps links in cm"},
+                "c_bicep_r": {"type": "DECIMAL", "description": "Bizeps rechts in cm"}
+            }
+        },
+        "activity_log": {
+            "description": "Trainingseinheiten",
+            "columns": {
+                "id": {"type": "UUID", "description": "ID (für Zählung von Einheiten)"},
+                "duration_minutes": {"type": "INTEGER", "description": "Trainingsdauer in Minuten"},
+                "perceived_exertion": {"type": "INTEGER", "description": "Belastungsempfinden (1-10)"},
+                "quality_rating": {"type": "INTEGER", "description": "Qualitätsbewertung (1-10)"}
+            }
+        },
+        "nutrition_log": {
+            "description": "Ernährungstagebuch",
+            "columns": {
+                "calories": {"type": "INTEGER", "description": "Kalorien in kcal"},
+                "protein_g": {"type": "DECIMAL", "description": "Protein in g"},
+                "carbs_g": {"type": "DECIMAL", "description": "Kohlenhydrate in g"},
+                "fat_g": {"type": "DECIMAL", "description": "Fett in g"}
+            }
+        },
+        "sleep_log": {
+            "description": "Schlafprotokoll",
+            "columns": {
+                "total_minutes": {"type": "INTEGER", "description": "Gesamtschlafdauer in Minuten"}
+            }
+        },
+        "vitals_baseline": {
+            "description": "Vitalwerte (morgens)",
+            "columns": {
+                "resting_hr": {"type": "INTEGER", "description": "Ruhepuls in bpm"},
+                "hrv_rmssd": {"type": "INTEGER", "description": "Herzratenvariabilität (RMSSD) in ms"},
+                "vo2_max": {"type": "DECIMAL", "description": "VO2 Max in ml/kg/min"},
+                "spo2": {"type": "INTEGER", "description": "Sauerstoffsättigung in %"},
+                "respiratory_rate": {"type": "INTEGER", "description": "Atemfrequenz pro Minute"}
+            }
+        },
+        "blood_pressure_log": {
+            "description": "Blutdruckmessungen",
+            "columns": {
+                "systolic": {"type": "INTEGER", "description": "Systolischer Blutdruck in mmHg"},
+                "diastolic": {"type": "INTEGER", "description": "Diastolischer Blutdruck in mmHg"},
+                "pulse": {"type": "INTEGER", "description": "Puls in bpm"}
+            }
+        },
+        "rest_days": {
+            "description": "Ruhetage",
+            "columns": {
+                "id": {"type": "UUID", "description": "ID (für Zählung von Ruhetagen)"}
+            }
+        }
+    }
+
+    return schema
+
 @router.get("/goal-types")
 def list_goal_type_definitions(session: dict = Depends(require_auth)):
     """

frontend/src/pages/AdminGoalTypesPage.jsx

@@ -4,6 +4,7 @@ import { api } from '../utils/api'
 
 export default function AdminGoalTypesPage() {
   const [goalTypes, setGoalTypes] = useState([])
+  const [schemaInfo, setSchemaInfo] = useState(null)
   const [loading, setLoading] = useState(true)
   const [error, setError] = useState(null)
   const [showForm, setShowForm] = useState(false)
@@ -42,9 +43,14 @@ export default function AdminGoalTypesPage() {
     setLoading(true)
     setError(null)
     try {
-      const data = await api.listGoalTypeDefinitions()
+      const [typesData, schema] = await Promise.all([
-      console.log('[DEBUG] Loaded goal types:', data)
+        api.listGoalTypeDefinitions(),
-      setGoalTypes(data || [])
+        api.getSchemaInfo()
+      ])
+      console.log('[DEBUG] Loaded goal types:', typesData)
+      console.log('[DEBUG] Loaded schema info:', schema)
+      setGoalTypes(typesData || [])
+      setSchemaInfo(schema || {})
     } catch (err) {
       console.error('[ERROR] Failed to load goal types:', err)
       setError(`Fehler beim Laden der Goal Types: ${err.message || err.toString()}`)
@@ -375,25 +381,59 @@ export default function AdminGoalTypesPage() {
               <div style={{ display: 'grid', gridTemplateColumns: '1fr 1fr', gap: 12 }}>
                 <div>
                   <label className="form-label">Tabelle</label>
-                  <input
+                  {schemaInfo ? (
-                    type="text"
+                    <select
-                    className="form-input"
+                      className="form-input"
-                    style={{ width: '100%' }}
+                      style={{ width: '100%' }}
-                    value={formData.source_table}
+                      value={formData.source_table}
-                    onChange={e => setFormData(f => ({ ...f, source_table: e.target.value }))}
+                      onChange={e => setFormData(f => ({ ...f, source_table: e.target.value, source_column: '' }))}
-                    placeholder="z.B. meditation_log"
+                    >
-                  />
+                      <option value="">-- Optional --</option>
+                      {Object.entries(schemaInfo).map(([table, info]) => (
+                        <option key={table} value={table} title={info.description}>
+                          {table} - {info.description}
+                        </option>
+                      ))}
+                    </select>
+                  ) : (
+                    <input
+                      type="text"
+                      className="form-input"
+                      style={{ width: '100%' }}
+                      value={formData.source_table}
+                      onChange={e => setFormData(f => ({ ...f, source_table: e.target.value }))}
+                      placeholder="Lade Schema..."
+                      disabled
+                    />
+                  )}
                 </div>
                 <div>
                   <label className="form-label">Spalte</label>
-                  <input
+                  {schemaInfo && formData.source_table && schemaInfo[formData.source_table] ? (
-                    type="text"
+                    <select
-                    className="form-input"
+                      className="form-input"
-                    style={{ width: '100%' }}
+                      style={{ width: '100%' }}
-                    value={formData.source_column}
+                      value={formData.source_column}
-                    onChange={e => setFormData(f => ({ ...f, source_column: e.target.value }))}
+                      onChange={e => setFormData(f => ({ ...f, source_column: e.target.value }))}
-                    placeholder="z.B. duration_minutes"
+                    >
-                  />
+                      <option value="">-- Wählen --</option>
+                      {Object.entries(schemaInfo[formData.source_table].columns).map(([col, info]) => (
+                        <option key={col} value={col} title={info.description}>
+                          {col} - {info.description}
+                        </option>
+                      ))}
+                    </select>
+                  ) : (
+                    <input
+                      type="text"
+                      className="form-input"
+                      style={{ width: '100%' }}
+                      value={formData.source_column}
+                      onChange={e => setFormData(f => ({ ...f, source_column: e.target.value }))}
+                      placeholder={formData.source_table ? "Spalte wählen..." : "Erst Tabelle wählen"}
+                      disabled={!formData.source_table}
+                    />
+                  )}
                 </div>
               </div>
 

frontend/src/utils/api.js

@@ -344,6 +344,7 @@ export const api = {
   createGoalType:          (d)    => req('/goals/goal-types', json(d)),
   updateGoalType:          (id,d) => req(`/goals/goal-types/${id}`, jput(d)),
   deleteGoalType:          (id)   => req(`/goals/goal-types/${id}`, {method:'DELETE'}),
+  getSchemaInfo:           ()     => req('/goals/schema-info'),
 
   // Training Phases
   listTrainingPhases:     ()      => req('/goals/phases'),