- Added `HindsightSessionState` to `AgentSession` and bound hindsight lifecycle hooks to session state.
- Removed global hindsight state/queue handling and replaced it with per-session `HindsightRetainQueue` batching and scoped flushing.
- Reworked recall, reflect, and retain tools to use `session.getHindsightSessionState()` instead of sessionId-based lookup.
- Updated SDK/task/backend/controller flows to pass `session`/`parentHindsightSessionState`, scope `/memory` behavior, and document it in changelog.
- Updated runtime memory config loading and backend resolution so `memory.backend === "local"` now enables the local pipeline directly, while `memories.enabled` is treated only as a legacy migration input.
- Switched the `memory.backend` default to `off` and kept `memories.enabled` hidden from the Memory tab UI for migration compatibility.
- Adjusted memory runtime, resolver, and documentation/tests to match the new backend-selection semantics.
- Added a new optional `beforeAgentStartPrompt` hook to `MemoryBackend` and implemented it in the Hindsight backend to recall long-term context for the first turn.
- Updated `AgentSession` startup flow to inject the recalled context into the turn-specific system prompt before the first response is generated.
- Preserved `<hindsight_memories>` tags in Hindsight developer instructions and added tests for first-turn injection and state caching.
- Added `memory.backend` and `hindsight.*` settings schema with migration from `memories.enabled` legacy mode.
- Added Hindsight memory backend runtime modules for resolved config, client creation, bank ID derivation, and state lifecycle.
- Added off/local/hindsight backends and resolver wiring across SDK, commands, and compaction context.
- Added `hindsight_recall`, `hindsight_reflect`, and `hindsight_retain` tools with schema validation and backend gating.
- Added Memory tab metadata and symbols to expose backend selection in the settings UI.
- Added package export barrels and tests for bank ID, content formatting, and hindsight config env precedence.