feat: Bibliothek + Admin

- Bibliothek: grid, before/after slider, rename, download, folder assign, delete, multi-select
- Admin: stats+costs, OpenRouter key (masked/encrypted), budget, defaults, Picdrop config+test,
  models (list/add from OpenRouter/set default/delete), users (add/set password)
- api: items/:id PATCH+DELETE, folders CRUD, admin/{settings,stats,models,test-picdrop,users}
- lib/picdrop.ts (SFTP/FTPS test+upload, temp->rename)

src/pages/api/admin/models.ts

@@ -0,0 +1,45 @@
+import type { APIRoute } from 'astro';
+import { one, query } from '../../../lib/db';
+import { listImageModels } from '../../../lib/openrouter';
+
+export const prerender = false;
+const json = (b: unknown, s = 200) =>
+  new Response(JSON.stringify(b), { status: s, headers: { 'Content-Type': 'application/json' } });
+
+// GET: gespeicherte Modelle; ?available=1 zusätzlich die von OpenRouter verfügbaren.
+export const GET: APIRoute = async ({ url }) => {
+  const models = await query('SELECT * FROM models ORDER BY sort, label');
+  const out: any = { models };
+  if (url.searchParams.get('available') === '1') {
+    try {
+      const avail = await listImageModels();
+      out.available = avail.map((m: any) => ({
+        model_id: m.id, name: m.name,
+        supports_alpha: (m.supported_parameters?.background?.values || []).includes('transparent')
+          || !!m.supported_parameters?.background,
+      }));
+    } catch (e: any) { out.available_error = e?.friendly || 'Modellliste nicht abrufbar.'; }
+  }
+  return json(out);
+};
+
+// POST: Modell anlegen/aktualisieren (upsert by model_id) oder Aktion (toggle/default/delete).
+export const POST: APIRoute = async ({ request }) => {
+  const b = await request.json();
+  if (b.action === 'delete' && b.id) { await query('DELETE FROM models WHERE id=$1', [b.id]); return json({ ok: true }); }
+  if (b.action === 'default' && b.id) {
+    await query('UPDATE models SET is_default=false'); await query('UPDATE models SET is_default=true WHERE id=$1', [b.id]);
+    return json({ ok: true });
+  }
+  if (!b.model_id || !b.label) return json({ error: 'model_id + label nötig.' }, 400);
+  const existing = await one<{ id: string }>('SELECT id FROM models WHERE model_id=$1', [b.model_id]);
+  if (existing) {
+    await query(`UPDATE models SET label=$2, description=$3, active=$4, supports_alpha=$5, sort=$6 WHERE id=$1`,
+      [existing.id, b.label, b.description || null, b.active ?? true, b.supports_alpha ?? false, b.sort ?? 0]);
+    return json({ id: existing.id });
+  }
+  const row = await one(`INSERT INTO models (model_id, label, description, active, supports_alpha, sort)
+    VALUES ($1,$2,$3,$4,$5,$6) RETURNING *`,
+    [b.model_id, b.label, b.description || null, b.active ?? true, b.supports_alpha ?? false, b.sort ?? 0]);
+  return json({ model: row });
+};