feat: model selection+visibility, better filenames, picdrop direct upload + configurable gallery

- studio: quality/model selector (friendly names from active models); library shows model used
- seed 2 models (Schnell/Beste Qualitaet); GET /api/models for studio+library
- filename: YYYY-MM-DD_motif_format.png (was redundant slug, no date)
- picdrop: direct upload to final name (fix .tmp- leftover from failed rename on picdrop); cleanupTmp helper
- configurable default gallery (migration 003, settings + admin field); base_path=SFTP root, gallery=subfolder

src/components/LibraryApp.tsx

@@ -1,22 +1,25 @@
 import React, { useState, useEffect, useCallback } from 'react';
 
 interface Item { id: string; filename: string; output_px: string; has_alpha: boolean;
-  folder_id: string | null; by_name: string; tasks: string[]; delivery_status: string; }
+  folder_id: string | null; by_name: string; tasks: string[]; delivery_status: string; model_used: string; }
 
 export default function LibraryApp() {
   const [items, setItems] = useState<Item[]>([]);
   const [folders, setFolders] = useState<any[]>([]);
+  const [models, setModels] = useState<any[]>([]);
+  const modelLabel = (id: string) => models.find((m) => m.model_id === id)?.label || null;
   const [sel, setSel] = useState<Set<string>>(new Set());
   const [compare, setCompare] = useState<Item | null>(null);
   const [toast, setToast] = useState<string | null>(null);
   const notify = (t: string) => { setToast(t); setTimeout(() => setToast(null), 2400); };
 
   const load = useCallback(async () => {
-    const [i, f] = await Promise.all([
+    const [i, f, m] = await Promise.all([
       fetch('/api/items').then((r) => r.json()).catch(() => ({ items: [] })),
       fetch('/api/folders').then((r) => r.json()).catch(() => ({ folders: [] })),
+      fetch('/api/models').then((r) => r.json()).catch(() => ({ models: [] })),
     ]);
-    setItems(i.items || []); setFolders(f.folders || []);
+    setItems(i.items || []); setFolders(f.folders || []); setModels(m.models || []);
   }, []);
   useEffect(() => { load(); }, [load]);
 
@@ -67,7 +70,7 @@ export default function LibraryApp() {
                 <span className="haken">{sel.has(v.id) ? '✓' : ''}</span>
               </div>
               <input className="name" defaultValue={v.filename || ''} onBlur={(e) => rename(v.id, e.target.value)} />
-              <div className="meta">{(v.tasks || []).join(' · ')}{v.output_px ? ` · ${v.output_px}px` : ''}{v.has_alpha ? ' · transparent' : ''}
+              <div className="meta">{(v.tasks || []).join(' · ')}{v.output_px ? ` · ${v.output_px}px` : ''}{v.has_alpha ? ' · transparent' : ''}{modelLabel(v.model_used) ? ` · ${modelLabel(v.model_used)}` : ''}
                 {v.delivery_status === 'delivered' && <span className="dbadge ok">Picdrop ✓</span>}
                 {v.delivery_status === 'pending' && <span className="dbadge">Picdrop …</span>}
                 {v.delivery_status === 'failed' && <span className="dbadge err">Picdrop ✕</span>}