feat: global placeholder export with values (Settings page)

Zentraler Export aller verfügbaren Platzhalter mit aktuellen Werten.

Backend:
- GET /api/prompts/placeholders/export-values
  - Returns all placeholders organized by category
  - Includes resolved values for current profile
  - Includes metadata (description, example)
  - Flat list + categorized structure

Frontend SettingsPage:
- Button "📊 Platzhalter exportieren"
- Downloads: placeholders-{profile}-{date}.json
- Shows all 38+ placeholders with current values
- Useful for:
  - Understanding available data
  - Debugging prompt templates
  - Verifying placeholder resolution

Frontend api.js:
- exportPlaceholderValues()

Export Format:
{
  "export_date": "2026-03-26T...",
  "profile_id": "...",
  "count": 38,
  "all_placeholders": { "name": "Lars", ... },
  "placeholders_by_category": {
    "Profil": [...],
    "Körper": [...],
    ...
  }
}

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

backend/routers/prompts.py

@@ -217,6 +217,54 @@ def list_placeholders(session: dict=Depends(require_auth)):
     return get_placeholder_catalog(profile_id)
 
 
+@router.get("/placeholders/export-values")
+def export_placeholder_values(session: dict = Depends(require_auth)):
+    """
+    Export all available placeholders with their current resolved values.
+
+    Returns JSON export suitable for download with all placeholders
+    resolved for the current user's profile.
+    """
+    from datetime import datetime
+    profile_id = session['profile_id']
+
+    # Get all resolved placeholder values
+    resolved_values = get_placeholder_example_values(profile_id)
+
+    # Clean up keys (remove {{ }})
+    cleaned_values = {
+        key.replace('{{', '').replace('}}', ''): value
+        for key, value in resolved_values.items()
+    }
+
+    # Get catalog for metadata
+    catalog = get_placeholder_catalog(profile_id)
+
+    # Organize by category with metadata
+    export_data = {
+        'export_date': datetime.now().isoformat(),
+        'profile_id': profile_id,
+        'placeholders_by_category': {}
+    }
+
+    for category, items in catalog.items():
+        export_data['placeholders_by_category'][category] = []
+        for item in items:
+            key = item['key'].replace('{{', '').replace('}}', '')
+            export_data['placeholders_by_category'][category].append({
+                'key': item['key'],
+                'description': item['description'],
+                'value': cleaned_values.get(key, 'nicht verfügbar'),
+                'example': item.get('example')
+            })
+
+    # Also include flat list for easy access
+    export_data['all_placeholders'] = cleaned_values
+    export_data['count'] = len(cleaned_values)
+
+    return export_data
+
+
 # ── KI-Assisted Prompt Engineering ───────────────────────────────────────────
 
 async def call_openrouter(prompt: str, max_tokens: int = 1500) -> str:

frontend/src/pages/SettingsPage.jsx

@@ -251,6 +251,23 @@ export default function SettingsPage() {
     setEditingId(null)
   }
 
+  const handleExportPlaceholders = async () => {
+    try {
+      const data = await api.exportPlaceholderValues()
+      const blob = new Blob([JSON.stringify(data, null, 2)], { type: 'application/json' })
+      const url = URL.createObjectURL(blob)
+      const a = document.createElement('a')
+      a.href = url
+      a.download = `placeholders-${activeProfile?.name || 'profile'}-${new Date().toISOString().split('T')[0]}.json`
+      document.body.appendChild(a)
+      a.click()
+      document.body.removeChild(a)
+      URL.revokeObjectURL(url)
+    } catch (e) {
+      alert('Fehler beim Export: ' + e.message)
+    }
+  }
+
   return (
     <div>
       <h1 className="page-title">Einstellungen</h1>
@@ -409,6 +426,16 @@ export default function SettingsPage() {
                 <span className="badge-button-description">maschinenlesbar, alles in einer Datei</span>
               </div>
             </button>
+            <button className="btn btn-full"
+              onClick={handleExportPlaceholders}
+              style={{ background: 'var(--surface2)', border: '1px solid var(--border)' }}>
+              <div className="badge-button-layout">
+                <div className="badge-button-header">
+                  <span><BarChart3 size={14}/> Platzhalter exportieren</span>
+                </div>
+                <span className="badge-button-description">alle verfügbaren Platzhalter mit aktuellen Werten</span>
+              </div>
+            </button>
           </>}
         </div>
         <p style={{fontSize:11,color:'var(--text3)',marginTop:8}}>

frontend/src/utils/api.js

@@ -326,4 +326,7 @@ export const api = {
     if (overwrite) params.append('overwrite', 'true')
     return req(`/prompts/import?${params}`, json(data))
   },
+
+  // Placeholder Export
+  exportPlaceholderValues: ()     => req('/prompts/placeholders/export-values'),
 }