feat: surface task execution progress across Host Agent and Cloud

Host Agent now persists step-level execution detail locally (via a real
TaskMetadataStore/Timeline wired into TaskRunner) and reports a bounded
in-progress snapshot piggybacked on lease renewal. Cloud persists that
snapshot per active assignment and exposes it through the existing task
list/detail query path; Cloud Console renders it as a live badge. Host
Agent's local console gains authenticated, read-only task list and
detail/timeline pages (same-origin, server-rendered) with inlined
screenshots.

Also fixes a pre-existing gap in the shared Timeline: the actual
per-step LLM prompt is now recorded instead of the task goal, benefiting
both Runtime and Host Agent consoles. When a host uses the cloud planner
transport, each decide call's prompt and resulting tool decision are
durably logged in a new planner_decision_log table (with bounded
retention) and browsable from Cloud Console; direct-transport hosts
explicitly surface a "not reported" state.

Includes Alembic migrations 0008 (progress columns on scheduled_tasks)
and 0009 (planner_decision_log), bounded Host-Agent-local retention,
dual-backend repository parity, and Vitest + pytest coverage. Task 6.5
(manual end-to-end device verification) remains.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/device-host-agent/host_agent/app.py

@@ -22,10 +22,14 @@ from host_agent.lease import ActiveAssignmentRunner
 from host_agent.local_account import LocalAccountStore
 from host_agent.policy_cache import HostPolicyCacheStore
 from host_agent.processor import AssignmentProcessingResult, AssignmentProcessor
+from host_agent.retention import prune_task_history
 from host_agent.status import AgentStatusTracker
 from host_agent.web.app import create_console_app
 from host_agent.web.auth import SessionManager
+from storage.artifact_store import ArtifactStore
 from storage.device_config import DeviceConfigStore
+from storage.task_metadata import TaskMetadataStore
+from storage.timeline import Timeline
 
 
 @dataclass
@@ -178,6 +182,16 @@ def create_application(
     console_enrollment_client: HostAgentEnrollmentClient | None = None
     if resolved_config.enrollment_managed:
         console_enrollment_client = HostAgentEnrollmentClient(resolved_config)
+    metadata_store = TaskMetadataStore(db_path=resolved_config.task_progress_db_path)
+    timeline = Timeline(ArtifactStore(root=resolved_config.task_artifact_dir))
+    executor = AssignmentExecutor(
+        create_execution_factories(
+            resolved_manager,
+            metadata_store=metadata_store,
+            timeline=timeline,
+            host_agent_config=resolved_config,
+        )
+    )
     console_app = create_console_app(
         config=resolved_config,
         manager=resolved_manager,
@@ -190,6 +204,9 @@ def create_application(
             ttl_seconds=resolved_config.console_session_ttl_seconds
         ),
         enrollment_client=console_enrollment_client,
+        metadata_store=metadata_store,
+        timeline=timeline,
+        executor=executor,
     )
     console_server = _EmbeddedConsoleServer(
         uvicorn.Config(
@@ -215,19 +232,18 @@ def create_application(
             revision=revision
         ),
     )
-    executor = AssignmentExecutor(
-        create_execution_factories(
-            resolved_manager,
-            host_agent_config=resolved_config,
-        )
-    )
     active_runner = ActiveAssignmentRunner(client, executor)
     processor = AssignmentProcessor(
         client,
         active_runner,
         status_tracker=status_tracker,
-        on_result=lambda assignment, result: _record_assignment_history(
-            history_store, assignment, result
+        on_result=lambda assignment, result: _on_assignment_finished(
+            history_store,
+            metadata_store,
+            timeline,
+            resolved_config,
+            assignment,
+            result,
         ),
     )
     dependency_supervisor: DependencySupervisor | None = None
@@ -245,6 +261,18 @@ def create_application(
     )
 
 
+def _on_assignment_finished(
+    history_store: ConsoleHistoryStore,
+    metadata_store: TaskMetadataStore,
+    timeline: Timeline,
+    config: HostAgentConfig,
+    assignment: AssignmentModel,
+    result: AssignmentProcessingResult,
+) -> None:
+    _record_assignment_history(history_store, assignment, result)
+    _prune_task_history(metadata_store, timeline, config)
+
+
 def _record_assignment_history(
     history_store: ConsoleHistoryStore,
     assignment: AssignmentModel,
@@ -260,6 +288,17 @@ def _record_assignment_history(
     )
 
 
+def _prune_task_history(
+    metadata_store: TaskMetadataStore,
+    timeline: Timeline,
+    config: HostAgentConfig,
+) -> None:
+    try:
+        prune_task_history(metadata_store, timeline, config=config)
+    except Exception:
+        pass
+
+
 def _configured_device_manager(
     config_store: DeviceConfigStore,
     *,