feat: Add Placeholder Metadata Export to Admin Panel

Adds download functionality for complete placeholder metadata catalog.

Backend:
- Fix: None-template handling in placeholder_metadata_extractor.py
  - Prevents TypeError when template is None in ai_prompts
- New endpoint: GET /api/prompts/placeholders/export-catalog-zip
  - Generates ZIP with 4 files: JSON catalog, Markdown catalog, Gap Report, Export Spec
  - Admin-only endpoint with on-the-fly generation
  - Returns streaming ZIP download

Frontend:
- Admin Panel: New "Placeholder Metadata Export" section
  - Button: "Complete JSON exportieren" - Downloads extended JSON
  - Button: "Complete ZIP" - Downloads all 4 catalog files as ZIP
  - Displays file descriptions
- api.js: Added exportPlaceholdersExtendedJson() function

Features:
- Non-breaking: Existing endpoints unchanged
- In-memory ZIP generation (no temp files)
- Formatted filenames with date
- Admin-only access for ZIP download
- JSON download available for all authenticated users

Use Cases:
- Backup/archiving of placeholder metadata
- Offline documentation access
- Import into other tools
- Compliance reporting

Files in ZIP:
1. PLACEHOLDER_CATALOG_EXTENDED.json - Machine-readable metadata
2. PLACEHOLDER_CATALOG_EXTENDED.md - Human-readable catalog
3. PLACEHOLDER_GAP_REPORT.md - Unresolved fields analysis
4. PLACEHOLDER_EXPORT_SPEC.md - API specification

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

backend/placeholder_metadata_extractor.py

@@ -460,7 +460,8 @@ def analyze_placeholder_usage(profile_id: str) -> Dict[str, UsedBy]:
         # Analyze each prompt
         for prompt in prompts:
             # Check template
-            template = prompt.get('template', '')
+            template = prompt.get('template') or ''
+            if template:  # Only process if template is not empty/None
                 found_placeholders = re.findall(r'\{\{(\w+)\}\}', template)
 
                 for ph_key in found_placeholders:
@@ -474,7 +475,9 @@ def analyze_placeholder_usage(profile_id: str) -> Dict[str, UsedBy]:
             if stages:
                 for stage in stages:
                     for stage_prompt in stage.get('prompts', []):
-                        template = stage_prompt.get('template', '')
+                        template = stage_prompt.get('template') or ''
+                        if not template:  # Skip if template is None/empty
+                            continue
                         found_placeholders = re.findall(r'\{\{(\w+)\}\}', template)
 
                         for ph_key in found_placeholders:

backend/routers/prompts.py

@@ -8,7 +8,8 @@ import json
 import uuid
 import httpx
 from typing import Optional
-from fastapi import APIRouter, Depends, HTTPException
+from fastapi import APIRouter, Depends, HTTPException, Query
+from fastapi.responses import StreamingResponse
 
 from db import get_db, get_cursor, r2d
 from auth import require_auth, require_admin
@@ -436,6 +437,158 @@ def export_placeholder_values_extended(session: dict = Depends(require_auth)):
     return export_data
 
 
+@router.get("/placeholders/export-catalog-zip")
+def export_placeholder_catalog_zip(
+    token: Optional[str] = Query(None),
+    session: dict = Depends(require_admin)
+):
+    """
+    Export complete placeholder catalog as ZIP file.
+
+    Includes:
+    - PLACEHOLDER_CATALOG_EXTENDED.json
+    - PLACEHOLDER_CATALOG_EXTENDED.md
+    - PLACEHOLDER_GAP_REPORT.md
+    - PLACEHOLDER_EXPORT_SPEC.md
+
+    This generates the files on-the-fly and returns as ZIP.
+    Admin only.
+    """
+    import io
+    import zipfile
+    from datetime import datetime
+    from generate_placeholder_catalog import (
+        generate_json_catalog,
+        generate_markdown_catalog,
+        generate_gap_report_md,
+        generate_export_spec_md
+    )
+    from placeholder_metadata_extractor import build_complete_metadata_registry
+    from generate_complete_metadata import apply_manual_corrections, generate_gap_report
+
+    profile_id = session['profile_id']
+
+    try:
+        # Build registry
+        registry = build_complete_metadata_registry(profile_id)
+        registry = apply_manual_corrections(registry)
+        gaps = generate_gap_report(registry)
+
+        # Create in-memory ZIP
+        zip_buffer = io.BytesIO()
+
+        with zipfile.ZipFile(zip_buffer, 'w', zipfile.ZIP_DEFLATED) as zip_file:
+            # Generate each file content in memory and add to ZIP
+
+            # 1. JSON Catalog
+            all_metadata = registry.get_all()
+            json_catalog = {
+                "schema_version": "1.0.0",
+                "generated_at": datetime.now().isoformat(),
+                "normative_standard": "PLACEHOLDER_METADATA_REQUIREMENTS_V2_NORMATIVE.md",
+                "total_placeholders": len(all_metadata),
+                "placeholders": {key: meta.to_dict() for key, meta in sorted(all_metadata.items())}
+            }
+            zip_file.writestr(
+                'PLACEHOLDER_CATALOG_EXTENDED.json',
+                json.dumps(json_catalog, indent=2, ensure_ascii=False)
+            )
+
+            # 2. Markdown Catalog (simplified version)
+            by_category = registry.get_by_category()
+            md_lines = [
+                "# Placeholder Catalog (Extended)",
+                "",
+                f"**Generated:** {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}",
+                f"**Total Placeholders:** {len(all_metadata)}",
+                "",
+                "## Placeholders by Category",
+                ""
+            ]
+
+            for category, metadata_list in sorted(by_category.items()):
+                md_lines.append(f"### {category} ({len(metadata_list)} placeholders)")
+                md_lines.append("")
+                for metadata in sorted(metadata_list, key=lambda m: m.key):
+                    md_lines.append(f"- `{{{{{metadata.key}}}}}` - {metadata.description}")
+                md_lines.append("")
+
+            zip_file.writestr('PLACEHOLDER_CATALOG_EXTENDED.md', '\n'.join(md_lines))
+
+            # 3. Gap Report
+            gap_lines = [
+                "# Placeholder Metadata Gap Report",
+                "",
+                f"**Generated:** {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}",
+                f"**Total Placeholders:** {len(all_metadata)}",
+                "",
+                "## Gaps Summary",
+                ""
+            ]
+
+            for gap_type, placeholders in sorted(gaps.items()):
+                if placeholders:
+                    gap_lines.append(f"### {gap_type.replace('_', ' ').title()}")
+                    gap_lines.append(f"Count: {len(placeholders)}")
+                    gap_lines.append("")
+                    for ph in placeholders[:10]:  # Max 10 per type
+                        gap_lines.append(f"- {{{{{ph}}}}}")
+                    if len(placeholders) > 10:
+                        gap_lines.append(f"- ... and {len(placeholders) - 10} more")
+                    gap_lines.append("")
+
+            zip_file.writestr('PLACEHOLDER_GAP_REPORT.md', '\n'.join(gap_lines))
+
+            # 4. Export Spec (simplified)
+            spec_lines = [
+                "# Placeholder Export Specification",
+                "",
+                f"**Version:** 1.0.0",
+                f"**Generated:** {datetime.now().strftime('%Y-%m-%d %H:%M:%S')}",
+                "",
+                "## API Endpoints",
+                "",
+                "### Extended Export",
+                "",
+                "```",
+                "GET /api/prompts/placeholders/export-values-extended",
+                "Header: X-Auth-Token: <token>",
+                "```",
+                "",
+                "Returns complete metadata for all 116 placeholders.",
+                "",
+                "### ZIP Export (Admin)",
+                "",
+                "```",
+                "GET /api/prompts/placeholders/export-catalog-zip",
+                "Header: X-Auth-Token: <token>",
+                "```",
+                "",
+                "Returns ZIP with all catalog files.",
+            ]
+
+            zip_file.writestr('PLACEHOLDER_EXPORT_SPEC.md', '\n'.join(spec_lines))
+
+        # Prepare ZIP for download
+        zip_buffer.seek(0)
+
+        filename = f"placeholder-catalog-{datetime.now().strftime('%Y-%m-%d')}.zip"
+
+        return StreamingResponse(
+            io.BytesIO(zip_buffer.read()),
+            media_type="application/zip",
+            headers={
+                "Content-Disposition": f"attachment; filename={filename}"
+            }
+        )
+
+    except Exception as e:
+        raise HTTPException(
+            status_code=500,
+            detail=f"Failed to generate ZIP: {str(e)}"
+        )
+
+
 # ── KI-Assisted Prompt Engineering ───────────────────────────────────────────
 
 async def call_openrouter(prompt: str, max_tokens: int = 1500) -> str:

frontend/src/pages/AdminPanel.jsx

@@ -502,6 +502,53 @@ export default function AdminPanel() {
           </Link>
         </div>
       </div>
+
+      {/* Placeholder Metadata Export Section */}
+      <div className="card section-gap" style={{marginTop:16}}>
+        <div style={{fontWeight:700,fontSize:14,marginBottom:12,display:'flex',alignItems:'center',gap:6}}>
+          <Settings size={16} color="var(--accent)"/> Placeholder Metadata Export (v1.0)
+        </div>
+        <div style={{fontSize:12,color:'var(--text3)',marginBottom:12,lineHeight:1.5}}>
+          Exportiere vollständige Metadaten aller 116 Placeholders. Normative Compliance v1.0.0.
+        </div>
+        <div style={{display:'grid',gap:8}}>
+          <button className="btn btn-secondary btn-full"
+            onClick={async()=>{
+              try {
+                const data = await api.exportPlaceholdersExtendedJson()
+                const blob = new Blob([JSON.stringify(data, null, 2)], {type:'application/json'})
+                const url = window.URL.createObjectURL(blob)
+                const a = document.createElement('a')
+                a.href = url
+                a.download = `placeholder-metadata-extended-${new Date().toISOString().split('T')[0]}.json`
+                a.click()
+                window.URL.revokeObjectURL(url)
+              } catch(e) {
+                alert('Fehler beim Export: '+e.message)
+              }
+            }}>
+            📄 Complete JSON exportieren
+          </button>
+          <button className="btn btn-secondary btn-full"
+            onClick={async()=>{
+              try {
+                const token = localStorage.getItem('bodytrack_token')
+                const a = document.createElement('a')
+                a.href = `/api/prompts/placeholders/export-catalog-zip?token=${token}`
+                a.download = `placeholder-catalog-${new Date().toISOString().split('T')[0]}.zip`
+                a.click()
+              } catch(e) {
+                alert('Fehler beim Export: '+e.message)
+              }
+            }}>
+            📦 Complete ZIP (JSON + Markdown + Reports)
+          </button>
+        </div>
+        <div style={{fontSize:11,color:'var(--text3)',marginTop:8,lineHeight:1.5}}>
+          <strong>JSON:</strong> Maschinenlesbare Metadaten aller Placeholders<br/>
+          <strong>ZIP:</strong> Katalog (JSON + MD), Gap Report, Export Spec (4 Dateien)
+        </div>
+      </div>
     </div>
   )
 }

frontend/src/utils/api.js

@@ -390,4 +390,7 @@ export const api = {
   getSleepDurationQualityChart:   (days=28) => req(`/charts/sleep-duration-quality?days=${days}`),
   getSleepDebtChart:              (days=28) => req(`/charts/sleep-debt?days=${days}`),
   getVitalSignsMatrixChart:       (days=7)  => req(`/charts/vital-signs-matrix?days=${days}`),
+
+  // Placeholder Metadata Export (v1.0)
+  exportPlaceholdersExtendedJson: () => req('/prompts/placeholders/export-values-extended'),
 }