- Drive chat list, timeline and forward picker from SwiftData @Query instead of AppModel's in-memory arrays; inject the per-account ModelContext from RootView with an in-memory fallback. - Physically delete locally deleted messages (context.delete) and purge rows marked deleted by older builds on store open, so @Query views never resurrect them. - Delete the legacy JSON snapshot only after a successful import save and restore the completeUntilFirstUserAuthentication data protection attribute on the store file. - Mirror the old ChatArchive tolerant decoding in LegacyArchiveImporter so snapshots from older schema versions (missing reactions, isGroupMessage, roster fields) still import. - Cover the new behaviour in ArchiveStoreTests and guard it with new verify.sh invariants; update AGENTS.md, ARCHITECTURE.md and SECURITY.md.