- Added comprehensive tests for downshifting model behavior, including plan nudge injection and completion safety mechanisms.
- Verified session persistence accuracy by validating that from-disk rebuilds match the live agent state.
- Confirmed correct cache key propagation during tan commands to ensure provider caching is preserved.
- Removed obsolete reasoning slide tests.
- Clear inherited todo list state and persist empty edit at fork creation to prevent parent task reminders from affecting the tangential session.
- Re-inject the fork notice after each auto-compaction event to ensure the boundary between the parent and child session survives history summarization.
- Align the provider cache key with the parent's actual pinned key to correctly mirror cached session context.
- Update `AgentSession` to perform a full entry rewrite during tool result pruning to ensure session files match pruned state for reliable resuming and branching.
- Initialized session metadata including system prompt, task, and toolset within the controller.
- Added session initialization tracking to the clone creation flow to ensure session state visibility.
- Updated unit tests to verify that session initialization data is correctly appended when a tan is created.
- Forwarded `parentAgentId` through task and eval launch paths when spawning subagents.
- Mapped `parentAgentId` to `parentId` in `createAgentSession`.
- Passed each caller's session `getAgentId` (or `MAIN_AGENT_ID`) as the parent for spawned agents.
- Removed the streaming guard that previously rejected /tan while the parent response was still generating.
- Passed "deliverAs: \"nextTurn\"" when sending the background dispatch breadcrumb and kept "triggerTurn: false" so an in-flight turn is not steered.
- Skipped rebuilding chat messages during streaming sessions and updated tests to cover the non-blocking dispatch path.
- Added a new SessionManager.forkFrom test confirming terminal breadcrumb suppression while cloning source session history under a new parent session.
- Updated TanCommandController test fixtures with required assistant message API, provider, model, and completion metadata.
- Added `/tan` slash command registration and interactive handling.
- Added TanCommandController validation and async task scheduling for `/tan` dispatch.
- Added session cloning that suppresses breadcrumbs, copies artifacts, and handles abort cleanup.
- Added `promptCacheKey` support in Agent and inherited `providerPromptCacheKey` in session creation.