fix: add dashboard weight enforcement and fix hover tooltips

- Dashboard QuickWeight: Feature limit enforcement hinzugefügt
- Hover-Tooltip Fix: Button in div wrapper (disabled buttons zeigen keine nativen tooltips)
- Error handling für Dashboard weight input
- Konsistentes UX über alle Eingabe-Screens

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

frontend/src/pages/CaliperScreen.jsx

@@ -72,15 +72,19 @@ function CaliperForm({ form, setForm, profile, onSave, onCancel, saveLabel='Spei
         </div>
       )}
       <div style={{display:'flex',gap:6,marginTop:8}}>
+        <div
+          title={usage && !usage.allowed ? `Limit erreicht (${usage.used}/${usage.limit}). Kontaktiere den Admin oder warte bis zum nächsten Reset.` : ''}
+          style={{flex:1,display:'inline-block'}}
+        >
           <button
             className="btn btn-primary"
-          style={{flex:1, cursor: (usage && !usage.allowed) ? 'not-allowed' : 'pointer'}}
+            style={{width:'100%', cursor: (usage && !usage.allowed) ? 'not-allowed' : 'pointer'}}
             onClick={()=>onSave(bfPct, sex)}
             disabled={saving || (usage && !usage.allowed)}
-          title={usage && !usage.allowed ? `Limit erreicht (${usage.used}/${usage.limit}). Kontaktiere den Admin oder warte bis zum nächsten Reset.` : ''}
           >
             {(usage && !usage.allowed) ? '🔒 Limit erreicht' : saveLabel}
           </button>
+        </div>
         {onCancel && <button className="btn btn-secondary" style={{flex:1}} onClick={onCancel}><X size={13}/> Abbrechen</button>}
       </div>
     </div>

frontend/src/pages/CircumScreen.jsx

@@ -130,12 +130,15 @@ export default function CircumScreen() {
             {error}
           </div>
         )}
+        <div
+          title={circumUsage && !circumUsage.allowed ? `Limit erreicht (${circumUsage.used}/${circumUsage.limit}). Kontaktiere den Admin oder warte bis zum nächsten Reset.` : ''}
+          style={{display:'inline-block',width:'100%',marginTop:8}}
+        >
           <button
             className="btn btn-primary btn-full"
-          style={{marginTop:8, cursor: (circumUsage && !circumUsage.allowed) ? 'not-allowed' : 'pointer'}}
+            style={{cursor: (circumUsage && !circumUsage.allowed) ? 'not-allowed' : 'pointer'}}
             onClick={handleSave}
             disabled={saving || (circumUsage && !circumUsage.allowed)}
-          title={circumUsage && !circumUsage.allowed ? `Limit erreicht (${circumUsage.used}/${circumUsage.limit}). Kontaktiere den Admin oder warte bis zum nächsten Reset.` : ''}
           >
             {saved ? <><Check size={14}/> Gespeichert!</>
                    : saving ? '…'
@@ -143,6 +146,7 @@ export default function CircumScreen() {
                    : 'Speichern'}
           </button>
         </div>
+      </div>
 
       {/* Liste */}
       <div className="section-gap">

frontend/src/pages/Dashboard.jsx

@@ -27,33 +27,76 @@ function QuickWeight({ onSaved }) {
   const [input,  setInput]  = useState('')
   const [saving, setSaving] = useState(false)
   const [saved,  setSaved]  = useState(false)
+  const [error,  setError]  = useState(null)
+  const [weightUsage, setWeightUsage] = useState(null)
   const today = dayjs().format('YYYY-MM-DD')
 
+  const loadUsage = () => {
+    api.getFeatureUsage().then(features => {
+      const weightFeature = features.find(f => f.feature_id === 'weight_entries')
+      setWeightUsage(weightFeature)
+    }).catch(err => console.error('Failed to load usage:', err))
+  }
+
   useEffect(()=>{
     api.weightStats().then(s=>{
       if(s?.latest?.date===today) setInput(String(s.latest.weight))
     })
+    loadUsage()
   },[])
 
   const handleSave = async () => {
     const w=parseFloat(input); if(!w||w<20||w>300) return
     setSaving(true)
-    try{ await api.upsertWeight(today,w); setSaved(true); onSaved?.(); setTimeout(()=>setSaved(false),2000) }
-    finally{ setSaving(false) }
+    setError(null)
+    try{
+      await api.upsertWeight(today,w)
+      setSaved(true)
+      await loadUsage()  // Reload usage after save
+      onSaved?.()
+      setTimeout(()=>setSaved(false),2000)
+    } catch(err) {
+      console.error('Save failed:', err)
+      setError(err.message || 'Fehler beim Speichern')
+      setTimeout(()=>setError(null), 5000)
+    } finally {
+      setSaving(false)
+    }
   }
 
+  const isDisabled = saving || !input || (weightUsage && !weightUsage.allowed)
+  const tooltipText = weightUsage && !weightUsage.allowed
+    ? `Limit erreicht (${weightUsage.used}/${weightUsage.limit}). Kontaktiere den Admin oder warte bis zum nächsten Reset.`
+    : ''
+
   return (
+    <div>
+      {error && (
+        <div style={{padding:'8px 10px',background:'var(--danger-bg)',border:'1px solid var(--danger)',borderRadius:8,fontSize:12,color:'var(--danger)',marginBottom:8}}>
+          {error}
+        </div>
+      )}
       <div style={{display:'flex',gap:8,alignItems:'center'}}>
         <input type="number" min={20} max={300} step={0.1} className="form-input"
           style={{flex:1,fontSize:17,fontWeight:600,textAlign:'center'}}
           placeholder="kg eingeben" value={input} onChange={e=>setInput(e.target.value)}
-        onKeyDown={e=>e.key==='Enter'&&handleSave()}/>
+          onKeyDown={e=>e.key==='Enter'&&!isDisabled&&handleSave()}/>
         <span style={{fontSize:13,color:'var(--text3)'}}>kg</span>
-      <button className="btn btn-primary" style={{padding:'8px 14px'}}
-        onClick={handleSave} disabled={saving||!input}>
-        {saved?<Check size={15}/>:saving?<div className="spinner" style={{width:14,height:14}}/>:'Speichern'}
+        <div title={tooltipText} style={{display:'inline-block'}}>
+          <button
+            className="btn btn-primary"
+            style={{padding:'8px 14px', cursor: isDisabled ? 'not-allowed' : 'pointer'}}
+            onClick={handleSave}
+            disabled={isDisabled}
+          >
+            {saved ? <Check size={15}/>
+                   : saving ? <div className="spinner" style={{width:14,height:14}}/>
+                   : (weightUsage && !weightUsage.allowed) ? '🔒 Limit'
+                   : 'Speichern'}
           </button>
         </div>
+      </div>
+    </div>
   )
 }
 

frontend/src/pages/WeightScreen.jsx

@@ -111,11 +111,14 @@ export default function WeightScreen() {
             {error}
           </div>
         )}
+        <div
+          title={weightUsage && !weightUsage.allowed ? `Limit erreicht (${weightUsage.used}/${weightUsage.limit}). Kontaktiere den Admin oder warte bis zum nächsten Reset.` : ''}
+          style={{display:'inline-block',width:'100%'}}
+        >
           <button
             className="btn btn-primary btn-full"
             onClick={handleSave}
             disabled={saving || !newWeight || (weightUsage && !weightUsage.allowed)}
-          title={weightUsage && !weightUsage.allowed ? `Limit erreicht (${weightUsage.used}/${weightUsage.limit}). Kontaktiere den Admin oder warte bis zum nächsten Reset.` : ''}
             style={{cursor: (weightUsage && !weightUsage.allowed) ? 'not-allowed' : 'pointer'}}
           >
             {saved ? <><Check size={15}/> Gespeichert!</>
@@ -124,6 +127,7 @@ export default function WeightScreen() {
                    : 'Speichern'}
           </button>
         </div>
+      </div>
 
       {/* Chart */}
       {chartData.length >= 2 && (