# DS4 Context Engine 0.3.6

Status: published release on 2026-09-05; tag `v0.3.6`.

This coordinated release fixes a managed-context selection defect: a single oversized atomic conversation turn could cause the planner to discard turns that are still essential to the current request, and its own retrieval second pass could not recover them.

## Fixed

- **Immediate-predecessor rescue**: when the turn immediately preceding the current request exceeds the recent-tail cap but still fits the active target and hard budgets, the planner keeps it verbatim instead of closing the entire recent tail at that group. The tail closes after the rescue, so older turns keep their prior bounded behavior. Controlled by `context.rescueImmediatePredecessor` (default `true`).
- **Retrieval second chance**: retrieval now deduplicates against the entries the managed plan actually commits, not against Pi's native context. Before the retrieval pass, the runtime plans the context with mandatory supplements only, maps the committed messages back to Pi session entry IDs, and passes those IDs as the retrieval exclusion set. Entries the planner excludes (for example an oversized turn) can therefore reappear as bounded, source-labelled `retrieval` evidence instead of being silently lost.
- **Diagnostics**: a `context.excluded_oversized_turn` warning reports how many turn groups at or above the recent-tail cap were excluded, whether the immediate predecessor was rescued, and the active limits. The Context Manifest planning block records optional `rescuedImmediatePredecessor` and `oversizedTurnExclusions` counters, and `/context explain` surfaces both.

No validation, privacy, provenance, cancellation, fallback, canonical-history, or bounded-retention behavior was weakened. The runtime retry policy, compaction pipeline, and storage formats are unchanged.

## Compatibility and persistence

The context manifest adds only optional metadata fields. `ds4-context-config-v1`, `runtime-adapter-v1`, `ds4-context-persistence-tool-v1`, `ds4-context-persistence-result-v1`, SQLite schema 15, and migration checksums are unchanged.

## Package/version policy

The coordinated version is `0.3.6` for:

```text
ds4-context-core
ds4-context-reference-adapter
ds4-context-engine
```

Both adapters depend exactly on `ds4-context-core@0.3.6`. The packages were published manually under npm `latest`. GitHub Actions remains validation-only with OIDC and package-write permissions denied.

## Validation evidence

Local candidate verification on Node.js `26.5.1`:

- `npm run check`: 81 files and 518 tests passed (including planner rescue cases, second-chance retrieval integration, and entry-id mapping).
- `npm run quality:compare`: candidate quality `0.9875` versus baseline `0.808156`.
- `npm run schema:context-persistence`: 1,266 bytes and 317 estimated tokens; below the 1,500 absolute and 320 relative limits.
- `npm run latency:check -- <exact ds4-context-core@0.1.2>`: passed with ratio `1.082064`, at or below `1.10`.
- `npm run pack:check`: verified core (235 files), reference adapter (7 files), and Pi adapter (87 files) in a clean consumer.
- `npm pack --dry-run --json` for all three packages: passed with the same bounded inventories.
- `git diff --check`: passed.
- Protected CI, compatibility golden, Pi fixture, migration, canonical Pin/Memory, and persistence-tool contract files: unchanged except the intentional `compatibility-0.2.0.json` default addition.

- `npm run registry:check -- 0.3.6`: passed against all three exact published versions; `latest` resolves to `0.3.6` for every package.

Exact registry verification passed before the annotated tag and GitHub release were created.

## Documentation

- [`../CONTEXT_PLANNER.md`](../CONTEXT_PLANNER.md)
- [`../COMPACTION.md`](../COMPACTION.md)
- [`../RELEASING.md`](../RELEASING.md)
- [`0.3.5.md`](0.3.5.md)