refactor: enhance body history visualization logic and frontend labels

- Updated the `get_body_history_viz_bundle` function to retrieve the two most recent circumference measurements for improved data accuracy.
- Refactored the handling of previous measurement data to ensure comprehensive interpolation for body metrics.
- Modified frontend labels in the `buildBodyKpiTiles` function to provide clearer descriptions in German, enhancing user understanding of body metrics.

backend/data_layer/body_viz.py

@@ -231,7 +231,7 @@ def get_body_history_viz_bundle(profile_id: str, days: int) -> Dict[str, Any]:
                 FROM circumference_log
                 WHERE profile_id = %s AND date >= %s
                 ORDER BY date DESC
-                LIMIT 1
+                LIMIT 2
                 """,
                 (profile_id, cutoff),
             )
@@ -242,11 +242,13 @@ def get_body_history_viz_bundle(profile_id: str, days: int) -> Dict[str, Any]:
                 FROM circumference_log
                 WHERE profile_id = %s
                 ORDER BY date DESC
-                LIMIT 1
+                LIMIT 2
                 """,
                 (profile_id,),
             )
-        latest_circ_row = r2d(cur.fetchone())
+        circ_latest_desc = [r2d(r) for r in cur.fetchall()]
+        latest_circ_row = circ_latest_desc[0] if circ_latest_desc else None
+        prev_circ_row = circ_latest_desc[1] if len(circ_latest_desc) > 1 else None
 
         # Latest weight in window
         latest_w = w_points[-1] if w_points else None
@@ -334,14 +336,40 @@ def get_body_history_viz_bundle(profile_id: str, days: int) -> Dict[str, Any]:
         measurement["c_belly"] = safe_float(latest_circ_row.get("c_belly"))
     if latest_w:
         measurement["weight"] = safe_float(latest_w.get("weight"))
+    # Referenzdatum für „aktuell“: neueste verfügbare Quelle (Caliper > Umfang > Gewicht)
+    if not measurement.get("date"):
+        if latest_circ_row and latest_circ_row.get("date"):
+            measurement["date"] = latest_circ_row.get("date")
+        elif latest_w and latest_w.get("date"):
+            measurement["date"] = latest_w.get("date")
 
-    prev_for_interp = None
+    # Vorperiode: vorherige Caliper-Zeile + vorherige Umfangsmessung + vorheriges Gewicht (w_points[-2])
+    prev_for_interp: Optional[Dict[str, Any]] = {}
     if prev_cal:
-        prev_for_interp = {
-            "date": prev_cal.get("date"),
-            "body_fat_pct": safe_float(prev_cal.get("body_fat_pct")),
-            "lean_mass": safe_float(prev_cal.get("lean_mass")),
-        }
+        prev_for_interp["date"] = prev_cal.get("date")
+        prev_for_interp["body_fat_pct"] = safe_float(prev_cal.get("body_fat_pct"))
+        prev_for_interp["lean_mass"] = safe_float(prev_cal.get("lean_mass"))
+    if prev_circ_row:
+        prev_for_interp["c_waist"] = safe_float(prev_circ_row.get("c_waist"))
+        prev_for_interp["c_hip"] = safe_float(prev_circ_row.get("c_hip"))
+        prev_for_interp["c_belly"] = safe_float(prev_circ_row.get("c_belly"))
+        if not prev_for_interp.get("date") and prev_circ_row.get("date"):
+            prev_for_interp["date"] = prev_circ_row.get("date")
+    if len(w_points) >= 2:
+        prev_for_interp["weight"] = safe_float(w_points[-2].get("weight"))
+        if not prev_for_interp.get("date") and w_points[-2].get("date"):
+            prev_for_interp["date"] = w_points[-2].get("date")
+
+    if not prev_for_interp:
+        prev_for_interp = None
+    else:
+        # Mindestens ein vergleichbares Feld zur aktuellen Messung
+        has_cmp = any(
+            prev_for_interp.get(k) is not None
+            for k in ("body_fat_pct", "lean_mass", "weight", "c_waist", "c_belly")
+        )
+        if not has_cmp:
+            prev_for_interp = None
 
     tiles = get_body_interpretation_tiles(measurement, profile_ui, prev_for_interp)
 

frontend/src/pages/History.jsx

@@ -187,10 +187,10 @@ function buildBodyKpiTiles({
     const ok = summary.whr < (sex === 'm' ? 0.9 : 0.85)
     tiles.push({
       key: 'whr',
-      category: 'WHR',
+      category: 'Fettverteilung',
       icon: '📐',
       value: String(summary.whr),
-      sublabel: 'Taille ÷ Hüfte',
+      sublabel: 'WHR · Taille ÷ Hüfte',
       verdict: whrRule ? verdictShort(whrRule.status) : (ok ? 'Gut' : 'Hinweis'),
       status: whrRule?.status || (ok ? 'good' : 'warn'),
       hoverTop: whrRule?.title || 'Waist-Hip-Ratio',
@@ -203,10 +203,10 @@ function buildBodyKpiTiles({
     const ok = summary.whtr < 0.5
     tiles.push({
       key: 'whtr',
-      category: 'WHtR',
+      category: 'Taille/Größe',
       icon: '📏',
       value: String(summary.whtr),
-      sublabel: 'Taille ÷ Größe',
+      sublabel: 'WHtR · Taille ÷ Größe',
       verdict: whtrRule ? verdictShort(whtrRule.status) : (ok ? 'Gut' : 'Hinweis'),
       status: whtrRule?.status || (ok ? 'good' : 'warn'),
       hoverTop: whtrRule?.title || 'Waist-to-Height-Ratio',