feat: Share-Link Typ 'Nur Upload' (upload_only)

Dritter Link-Typ neben read und write:
- upload_only: Nur Dateien hochladen, kein Download, kein Ordnerinhalt
  sichtbar, Ordnername wird nicht angezeigt

Backend-Absicherung:
- GET /share/<token>/download gibt 403 bei upload_only
- POST /share/<token>/upload erlaubt upload_only + write
- GET /share/<token>/info gibt download_allowed zurueck

Frontend Share-Dialog:
- Drei Optionen: Nur Lesen / Lesen+Hochladen / Nur Upload
- Bestehende Links zeigen Typ an

Frontend ShareView:
- upload_only: Zeigt nur Upload-Zone, kein Dateiname, kein Download
- Hinweistext 'Dieser Link erlaubt nur das Hochladen von Dateien'

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/api/files.py

@@ -421,8 +421,8 @@ def create_share_link(file_id):
     max_downloads = data.get('max_downloads')
     permission = data.get('permission', 'read')
 
-    if permission not in ('read', 'write'):
-        return jsonify({'error': 'Berechtigung muss "read" oder "write" sein'}), 400
+    if permission not in ('read', 'write', 'upload_only'):
+        return jsonify({'error': 'Berechtigung muss "read", "write" oder "upload_only" sein'}), 400
 
     token = secrets.token_urlsafe(32)
     password_hash = None
@@ -498,7 +498,8 @@ def share_info(token):
         'mime_type': f.mime_type,
         'has_password': bool(link.password_hash),
         'permission': link.permission,
-        'upload_allowed': f.is_folder and link.permission == 'write',
+        'upload_allowed': f.is_folder and link.permission in ('write', 'upload_only'),
+        'download_allowed': link.permission in ('read', 'write'),
     }), 200
 
 
@@ -531,6 +532,9 @@ def share_download(token):
     if not link:
         return jsonify({'error': 'Link nicht gefunden'}), 404
 
+    if link.permission == 'upload_only':
+        return jsonify({'error': 'Dieser Link erlaubt nur Upload, keinen Download'}), 403
+
     if link.is_expired():
         return jsonify({'error': 'Link abgelaufen'}), 410
 
@@ -576,9 +580,9 @@ def share_upload(token):
     if link.is_expired():
         return jsonify({'error': 'Link abgelaufen'}), 410
 
-    # Check write permission
-    if link.permission != 'write':
-        return jsonify({'error': 'Dieser Link erlaubt nur Lesen'}), 403
+    # Check write/upload permission
+    if link.permission not in ('write', 'upload_only'):
+        return jsonify({'error': 'Dieser Link erlaubt keinen Upload'}), 403
 
     # Check password if set
     if link.password_hash:

frontend/src/views/FilesView.vue

@@ -184,7 +184,7 @@
             <div class="link-info">
               <code>{{ currentOrigin }}/share/{{ link.token }}</code>
               <small>
-                {{ link.permission === 'write' ? 'Lesen+Schreiben' : 'Nur Lesen' }}
+                {{ {read: 'Nur Lesen', write: 'Lesen+Schreiben', upload_only: 'Nur Upload'}[link.permission] || link.permission }}
                 | {{ link.download_count }} Downloads
                 <template v-if="link.expires_at"> | Bis {{ formatDate(link.expires_at) }}</template>
                 <template v-if="link.has_password"> | Passwortgeschuetzt</template>
@@ -255,7 +255,11 @@ const selectedShareUser = ref(null)
 const shareUserPermission = ref('read')
 const userSearchResults = ref([])
 const userPermOptions = [{ label: 'Lesen', value: 'read' }, { label: 'Schreiben', value: 'write' }, { label: 'Admin', value: 'admin' }]
-const linkPermOptions = [{ label: 'Nur Lesen (Download)', value: 'read' }, { label: 'Lesen + Hochladen (nur Ordner)', value: 'write' }]
+const linkPermOptions = [
+  { label: 'Nur Lesen (Download)', value: 'read' },
+  { label: 'Lesen + Hochladen (nur Ordner)', value: 'write' },
+  { label: 'Nur Upload (Ordner, kein Einblick)', value: 'upload_only' },
+]
 const shareLinkPermission = ref('read')
 const currentOrigin = window.location.origin
 const shareLoading = ref(false)

frontend/src/views/ShareView.vue

@@ -14,9 +14,10 @@
       </div>
 
       <div v-else-if="fileInfo" class="share-info">
-        <h2>{{ fileInfo.name }}</h2>
-        <p class="file-size" v-if="fileInfo.size && !fileInfo.is_folder">{{ formatSize(fileInfo.size) }}</p>
-        <Tag v-if="fileInfo.is_folder" value="Ordner" severity="info" />
+        <h2 v-if="fileInfo.permission !== 'upload_only'">{{ fileInfo.name }}</h2>
+        <h2 v-else>Datei-Upload</h2>
+        <p class="file-size" v-if="fileInfo.size && !fileInfo.is_folder && fileInfo.permission !== 'upload_only'">{{ formatSize(fileInfo.size) }}</p>
+        <Tag v-if="fileInfo.is_folder && fileInfo.permission !== 'upload_only'" value="Ordner" severity="info" />
 
         <div v-if="fileInfo.has_password && !authenticated" class="password-form">
           <p>Diese Freigabe ist passwortgeschuetzt.</p>
@@ -28,8 +29,8 @@
         </div>
 
         <div v-else class="actions-section">
-          <!-- Download (files only) -->
-          <div v-if="!fileInfo.is_folder" class="action-block">
+          <!-- Download (files only, not upload_only) -->
+          <div v-if="!fileInfo.is_folder && fileInfo.download_allowed" class="action-block">
             <Button
               label="Herunterladen"
               icon="pi pi-download"
@@ -38,6 +39,11 @@
             />
           </div>
 
+          <!-- Upload-only hint -->
+          <p v-if="fileInfo.permission === 'upload_only'" class="upload-only-hint">
+            Dieser Link erlaubt nur das Hochladen von Dateien.
+          </p>
+
           <!-- Upload (folders only) -->
           <div v-if="fileInfo.upload_allowed" class="action-block">
             <div class="upload-area"
@@ -216,4 +222,5 @@ onMounted(loadInfo)
 .upload-area p { margin: 0.5rem 0; color: var(--p-text-muted-color); font-size: 0.9rem; }
 .upload-progress { margin-top: 1rem; }
 .upload-progress p { font-size: 0.85rem; color: var(--p-text-muted-color); margin-top: 0.5rem; }
+.upload-only-hint { color: var(--p-text-muted-color); font-size: 0.9rem; margin-bottom: 1rem; }
 </style>