# Autonomous completion report — Increment 40

## Completed tranche

The requested continuation from Increment 39 has been implemented as a coherent vertical slice rather than additional visual placeholders. Server artifacts now use authenticated encryption, and supported client mutations can continue in IndexedDB and replay after reconnect.

## Key engineering outcomes

- Fail-closed encrypted upload path.
- Streaming authorised decryption.
- Encrypted previews and ZIP inventories.
- Safe serialised migration for multi-worker startup.
- Exactly-once chat replay evidence.
- Version-based stale-write rejection.
- Visible queue and conflict state.
- Production bundle now includes the offline module; unresolved ESM imports are stripped by the vendored build pipeline.

## Defects found and corrected during completion

- The original vendored build script did not include the new offline module and would have emitted an unresolved module import. The bundler now includes and sanitises it.
- Attachment-content compatibility assumed every mapping exposed warning metadata. It now safely handles legacy/test rows.
- Concurrent Gunicorn workers could have entered plaintext migration together. Migration now uses an inter-process lock.
- Multiple offline setting edits could create avoidable stale-version conflicts. Compatible pending edits are coalesced by endpoint.
- Newly created chat streams could observe stale React state. Current-conversation tracking now uses a ref during streaming.

## Deferred work

The broader Increment 38 module catalogue remains as documented in the feature matrix. Increment 40 is not represented as full build-spec conformance.