## ADDED Requirements

### Requirement: Host Agent records step-level execution detail for its in-process TaskRunner
The Host Agent SHALL construct its in-process `TaskRunner` with a durable metadata store and timeline so that every step transition (status, index, the actual prompt submitted to the LLM for that step, the model's resulting decision, result, and screenshot when captured) is persisted as it happens, rather than discarded when the assignment completes. The persisted prompt SHALL be the prompt actually sent to the LLM for that specific step, not the task's overall goal.

#### Scenario: A step completes during goal execution
- **WHEN** the Host Agent's `TaskRunner` completes a step while executing an assigned goal
- **THEN** the step's status, index, the actual per-step LLM prompt and response, tool call, result, and any captured screenshot are persisted to the Host Agent's local task metadata store and timeline before the next step begins

#### Scenario: An assignment finishes
- **WHEN** an assignment reaches a terminal state (succeeded or failed)
- **THEN** its full step history remains queryable from the Host Agent's local store after the in-memory `Task` object is discarded

### Requirement: Host-Agent-local task history is retained within a bounded window
The Host Agent SHALL prune persisted task metadata, timeline records, and associated screenshot artifacts once they exceed a configurable retention window or count, so that indefinite process uptime does not cause unbounded local disk growth.

#### Scenario: Retention window is exceeded
- **WHEN** a persisted task's age or position exceeds the configured retention threshold
- **THEN** the Host Agent removes that task's metadata row, timeline records, and screenshot artifacts from local storage

#### Scenario: Retention has not been exceeded
- **WHEN** a persisted task is within the configured retention threshold
- **THEN** its metadata, timeline records, and screenshot artifacts remain available for query

### Requirement: Host Agent local task storage is isolated from an unrelated local Runtime
The Host Agent SHALL use a configurable, Host-Agent-specific database and artifact path for its task metadata store and timeline, distinct from any local Runtime API's own task storage path, so that the two processes cannot silently collide or share state when run on the same machine.

#### Scenario: Host Agent and local Runtime run on the same machine
- **WHEN** both a Host Agent process and a local Runtime API process run on the same machine with their default configurations
- **THEN** each process reads and writes its own task metadata store and timeline without observing or modifying the other's data