fix: DataTable Button-Clicks mit .stop + Share-Link Debug-Logging

- Alle Buttons in der Datei-Tabelle haben jetzt @click.stop
  (Download, Teilen, Umbenennen, Loeschen) damit die DataTable
  den Click nicht verschluckt
- Debug-Logging in createShare() um Frontend-Fehler sichtbar zu machen

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

frontend/src/views/FilesView.vue

@@ -81,23 +81,23 @@
               v-if="!data.is_folder"
               icon="pi pi-download"
               text rounded size="small"
-              @click="downloadFile(data)"
+              @click.stop="downloadFile(data)"
             />
             <Button
               icon="pi pi-share-alt"
               text rounded size="small"
-              @click="openShare(data)"
+              @click.stop="openShare(data)"
             />
             <Button
               icon="pi pi-pencil"
               text rounded size="small"
-              @click="openRename(data)"
+              @click.stop="openRename(data)"
             />
             <Button
               icon="pi pi-trash"
               text rounded size="small"
               severity="danger"
-              @click="confirmDelete(data)"
+              @click.stop="confirmDelete(data)"
             />
           </div>
         </template>
@@ -588,12 +588,17 @@ async function removeUserShare(permId) {
 }
 
 async function createShare() {
-  if (!shareFile.value) return
+  console.log('createShare called, shareFile:', shareFile.value?.id, 'permission:', shareLinkPermission.value)
+  if (!shareFile.value) {
+    console.error('shareFile is null')
+    return
+  }
   shareLoading.value = true
   try {
     const opts = { permission: shareLinkPermission.value }
     if (sharePassword.value) opts.password = sharePassword.value
     if (shareExpiry.value) opts.expires_at = shareExpiry.value
+    console.log('Creating share link with opts:', opts)
     await filesStore.createShareLink(shareFile.value.id, opts)
     shareLinks.value = await filesStore.getShareLinks(shareFile.value.id)
     sharePassword.value = ''
@@ -601,7 +606,8 @@ async function createShare() {
     shareLinkPermission.value = 'read'
     toast.add({ severity: 'success', summary: 'Link erstellt', life: 3000 })
   } catch (err) {
-    toast.add({ severity: 'error', summary: 'Fehler', detail: err.response?.data?.error, life: 5000 })
+    console.error('createShare error:', err)
+    toast.add({ severity: 'error', summary: 'Fehler', detail: err.response?.data?.error || String(err), life: 5000 })
   } finally {
     shareLoading.value = false
   }