refactor: improve vital signs data handling and frontend display

- Introduced a new function `_merge_vitals_baseline_rows` to streamline the retrieval and merging of vital signs data, ensuring the latest non-empty values are prioritized.
- Updated SQL queries in `build_vital_signs_matrix_chart_payload` to enhance data retrieval efficiency and accuracy.
- Refactored the `renderVitalSigns` function in the `RecoveryDashboardOverview` component to improve handling of vital signs data, including better fallback messaging and chart rendering logic.
- Enhanced user feedback by providing clearer messages when no vital data is available, improving overall user experience.

backend/data_layer/recovery_chart_payloads.py

@@ -7,7 +7,7 @@ Ausgelagert aus routers/charts.py (Issue 53 / Layer 1).
 from __future__ import annotations
 
 from datetime import datetime, timedelta
-from typing import Any, Dict
+from typing import Any, Dict, Optional
 
 from db import get_db, get_cursor
 from data_layer.recovery_metrics import (
@@ -356,15 +356,38 @@ def build_sleep_debt_chart_payload(profile_id: str, days: int) -> Dict[str, Any]
     }
 
 
+VITAL_BASELINE_KEYS = ("resting_hr", "hrv", "vo2_max", "spo2", "respiratory_rate")
+
+
 def _vitals_row_has_any_value(row: Any) -> bool:
     if not row:
         return False
-    for k in ("resting_hr", "hrv", "vo2_max", "spo2", "respiratory_rate"):
+    for k in VITAL_BASELINE_KEYS:
         if row.get(k) is not None:
             return True
     return False
 
 
+def _merge_vitals_baseline_rows(rows: Any) -> tuple[Optional[Dict[str, Any]], Optional[Any]]:
+    """
+    Pro Kennzahl den jeweils neuesten nicht-leeren Wert (Zeilen sortiert: date DESC).
+    So können KPIs (Aggregation über Zeilen) Daten haben, obwohl die jüngste Zeile leer ist.
+    """
+    if not rows:
+        return None, None
+    merged: Dict[str, Any] = {k: None for k in VITAL_BASELINE_KEYS}
+    for row in rows:
+        for k in VITAL_BASELINE_KEYS:
+            if merged[k] is None and row.get(k) is not None:
+                merged[k] = row[k]
+        if all(merged[k] is not None for k in VITAL_BASELINE_KEYS):
+            break
+    if not _vitals_row_has_any_value(merged):
+        return None, None
+    newest_date = rows[0].get("date") if rows else None
+    return merged, newest_date
+
+
 def _bp_row_complete(row: Any) -> bool:
     return bool(row and row.get("systolic") is not None and row.get("diastolic") is not None)
 
@@ -381,10 +404,10 @@ def build_vital_signs_matrix_chart_payload(profile_id: str, days: int) -> Dict[s
         days = 365
     cutoff = (datetime.now() - timedelta(days=days)).strftime("%Y-%m-%d")
 
-    vitals_row = None
     bp_row = None
     vitals_measured_at = None
     bp_measured_at = None
+    vitals_for_items: Optional[Dict[str, Any]] = None
 
     with get_db() as conn:
         cur = get_cursor(conn)
@@ -393,27 +416,24 @@ def build_vital_signs_matrix_chart_payload(profile_id: str, days: int) -> Dict[s
                FROM vitals_baseline
                WHERE profile_id=%s AND date >= %s
                ORDER BY date DESC
-               LIMIT 1""",
+               LIMIT 200""",
             (profile_id, cutoff),
         )
-        vitals_row = cur.fetchone()
-        if vitals_row and vitals_row.get("date") is not None:
-            d = vitals_row["date"]
-            vitals_measured_at = d.isoformat() if hasattr(d, "isoformat") else str(d)
-
-        if not _vitals_row_has_any_value(vitals_row):
+        vitals_merged, vitals_date = _merge_vitals_baseline_rows(cur.fetchall())
+        if vitals_merged is None:
             cur.execute(
                 """SELECT date, resting_hr, hrv, vo2_max, spo2, respiratory_rate
                    FROM vitals_baseline
                    WHERE profile_id=%s
                    ORDER BY date DESC
-                   LIMIT 1""",
+                   LIMIT 400""",
                 (profile_id,),
             )
-            vitals_row = cur.fetchone()
-            if vitals_row and vitals_row.get("date") is not None:
-                d = vitals_row["date"]
-                vitals_measured_at = d.isoformat() if hasattr(d, "isoformat") else str(d)
+            vitals_merged, vitals_date = _merge_vitals_baseline_rows(cur.fetchall())
+        if vitals_merged is not None:
+            vitals_for_items = dict(vitals_merged)
+        if vitals_date is not None:
+            vitals_measured_at = vitals_date.isoformat() if hasattr(vitals_date, "isoformat") else str(vitals_date)
 
         cur.execute(
             """SELECT measured_at, systolic, diastolic
@@ -440,10 +460,6 @@ def build_vital_signs_matrix_chart_payload(profile_id: str, days: int) -> Dict[s
             if bp_row and bp_row.get("measured_at") is not None:
                 bp_measured_at = bp_row["measured_at"]
 
-    # Dict-like rows for assessment (exclude date/measured_at from value checks)
-    vitals_for_items = dict(vitals_row) if vitals_row else None
-    if vitals_for_items and "date" in vitals_for_items:
-        vitals_for_items = {k: v for k, v in vitals_for_items.items() if k != "date"}
     bp_for_items = None
     if bp_row:
         bp_for_items = {"systolic": bp_row.get("systolic"), "diastolic": bp_row.get("diastolic")}

frontend/src/components/RecoveryDashboardOverview.jsx

@@ -316,24 +316,57 @@ export default function RecoveryDashboardOverview({
   }
 
   const renderVitalSigns = () => {
-    if (!vitalsData || vitalsData.metadata?.confidence === 'insufficient') {
+    if (!vitalsData) {
       return (
         <div style={{ padding: 20, textAlign: 'center', color: 'var(--text3)', fontSize: 12 }}>
-          {vitalsData?.metadata?.message || 'Keine aktuellen Vitalwerte'}
+          Keine Vital-Matrix-Daten
         </div>
       )
     }
-    const items = vitalsData.metadata?.vital_items || []
-    const chartRows = items.map((it) => ({
+    const meta = vitalsData.metadata || {}
+    const items = meta.vital_items || []
+    const ds0 = vitalsData.data?.datasets?.[0]
+    const hasRawChart =
+      Array.isArray(vitalsData.data?.labels) &&
+      vitalsData.data.labels.length > 0 &&
+      Array.isArray(ds0?.data) &&
+      ds0.data.length > 0
+    const ins = meta.confidence === 'insufficient'
+    if (ins && items.length === 0 && !hasRawChart) {
+      return (
+        <div style={{ padding: 20, textAlign: 'center', color: 'var(--text3)', fontSize: 12 }}>
+          {meta.message || 'Keine aktuellen Vitalwerte'}
+        </div>
+      )
+    }
+
+    let chartRows = items.map((it) => ({
       name: it.label_de,
-      value: it.bar_value ?? 0,
+      value: Number(it.bar_value ?? 0),
       fill: barFillForTone(it.tone),
       tone: it.tone,
     }))
+    if (chartRows.length === 0 && hasRawChart) {
+      const bg = ds0.backgroundColor
+      chartRows = vitalsData.data.labels.map((name, i) => ({
+        name,
+        value: Number(ds0.data[i] ?? 0),
+        fill: Array.isArray(bg) ? bg[i] || '#1D9E75' : bg || '#1D9E75',
+        tone: 'neutral',
+      }))
+    }
 
-    const vitDate = vitalsData.metadata?.vitals_measured_at
-    const bpDate = vitalsData.metadata?.blood_pressure_measured_at
-    const disclaimer = vitalsData.metadata?.disclaimer_de
+    if (items.length === 0 && chartRows.length === 0) {
+      return (
+        <div style={{ padding: 20, textAlign: 'center', color: 'var(--text3)', fontSize: 12 }}>
+          Keine Vitalwerte zur Anzeige (Server lieferte weder Kennzeilen noch Diagrammdaten).
+        </div>
+      )
+    }
+
+    const vitDate = meta.vitals_measured_at
+    const bpDate = meta.blood_pressure_measured_at
+    const disclaimer = meta.disclaimer_de
 
     return (
       <>
@@ -391,6 +424,12 @@ export default function RecoveryDashboardOverview({
           </div>
         ) : null}
 
+        {items.length === 0 && chartRows.length > 0 ? (
+          <div style={{ fontSize: 11, color: 'var(--text3)', marginBottom: 8 }}>
+            Diagramm aus Server-Daten (ohne Zonen-Detail — bitte App aktualisieren oder Cache leeren).
+          </div>
+        ) : null}
+
         {chartRows.length > 0 ? (
           <>
             <div style={{ fontSize: 11, color: 'var(--text3)', marginBottom: 6 }}>