Weekly vault defragmentation. Runs a 5-phase structural audit: inbox hygiene, area completeness, project archival, MOC refresh, tag consistency, structure evolution, and generates a report. Triggers: EN: "defragment the vault", "reorganize the vault", "structural maintenance", "vault defrag", "weekly defrag". IT: "deframmenta il vault", "riorganizza il vault", "manutenzione strutturale", "defrag settimanale". FR: "defragmenter le vault", "reorganiser le vault". ES: "desfragmentar el vault", "reorganizar el vault". DE: "Vault defragmentieren", "Vault reorganisieren". PT: "desfragmentar o vault", "reorganizar o vault".