feat: mirror-all-to-NAS, content reset (danger zone), in-app changelog + CHANGELOG.md, How-To refresh

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XNQ8ghPfzAfsyVYd6HgFb6

src/lib/maintenance.ts

@@ -69,6 +69,21 @@ export async function purgeSources(): Promise<{ purged: number }> {
   return { purged };
 }
 
+/** Spiegelt alle fertigen Bilder aufs NAS (einmalige Nachsicherung). */
+export async function mirrorAllToNas(): Promise<{ mirrored: number; failed: number; total: number }> {
+  const { mirrorItemToNas, loadNasConfig } = await import('./nas');
+  if (!(await loadNasConfig())) return { mirrored: 0, failed: 0, total: 0 };
+  const rows = await query<{ id: string }>(
+    `SELECT id FROM items WHERE status='done' AND result_path IS NOT NULL
+       AND (nas_status IS NULL OR nas_status <> 'mirrored') ORDER BY created_at`);
+  let mirrored = 0, failed = 0;
+  for (const it of rows) {
+    const r = await mirrorItemToNas(it.id);
+    r.ok ? mirrored++ : failed++;
+  }
+  return { mirrored, failed, total: rows.length };
+}
+
 let timer: NodeJS.Timeout | null = null;
 /** Täglicher Retention-Lauf (falls in den Einstellungen aktiviert). */
 export function startMaintenance(): void {